US3809789A - Computor organ using harmonic limiting - Google Patents

Computor organ using harmonic limiting Download PDF

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Publication number
US3809789A
US3809789A US00314681A US31468172A US3809789A US 3809789 A US3809789 A US 3809789A US 00314681 A US00314681 A US 00314681A US 31468172 A US31468172 A US 31468172A US 3809789 A US3809789 A US 3809789A
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note
harmonic
amplitude
fourier
musical instrument
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R Deutsch
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Nippon Gakki Co Ltd
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Nippon Gakki Co Ltd
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Priority to DE2362050A priority patent/DE2362050C3/de
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    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10H—ELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE
    • G10H7/00—Instruments in which the tones are synthesised from a data store, e.g. computer organs
    • G10H7/08—Instruments in which the tones are synthesised from a data store, e.g. computer organs by calculating functions or polynomial approximations to evaluate amplitudes at successive sample points of a tone waveform
    • G10H7/10—Instruments in which the tones are synthesised from a data store, e.g. computer organs by calculating functions or polynomial approximations to evaluate amplitudes at successive sample points of a tone waveform using coefficients or parameters stored in a memory, e.g. Fourier coefficients
    • G10H7/105—Instruments in which the tones are synthesised from a data store, e.g. computer organs by calculating functions or polynomial approximations to evaluate amplitudes at successive sample points of a tone waveform using coefficients or parameters stored in a memory, e.g. Fourier coefficients using Fourier coefficients

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  • harmonic inhibit means 3,740,450 1973' L are provided for limiting the Fourier components in- 3,743,755 7/1973 Watson 84/].01 cluded in each amplitude computation only to those g; g E"' having frequencies below a certain value preferably 6U SC 6 3.. 1 3,515,792 6/1970 Deutsch 84/1.03 the nqrmal human hearmg rang? 19 Claims, 8 Drawing Figures AMPLITUDE ACCUMULATOR MULTIPLIER 55 cLEAn MEMORY ADDRESS IC" X (org); 5:
  • the present invention relates to a system for reducing the computational rate requirements of an elec tronic musical instrument wherein tones are produced by computing the amplitudes at successive sample points of a complex waveshape and converting these amplitudes to musical sounds as the computations are carried out.
  • the system limits the Fourier components calculated for each sample point to ones having a frequency below a selected value within the human hearing range.
  • the computational rate can be halved by concurrently calculating eight components in one processing channel and the other eight harmonics in asecnd, parallel channel.
  • An object of the present invention is to provide another approach for reducing the computational rate re- SUMMARY OF THE INVENTION
  • the musical waveshape is generated in real time. This advantageously (but not necessarily) is achieved by computing each sample point amplitude in a fixed time interval t,. All of the individual Fourier components are calculated within that interval.
  • the sample rate must be greater than the Nyquist frequencyf which is twice the frequency f;. 0f the highest Fourier component evaluated by the system.
  • the highest eight-foot pitch on a standard organ keyboard is C, which has a fundamental frequency f 2.093 kI-Iz. If 16 Fourier components are calculated to synthesize this tone, the highest frequency f evaluated by the organ corresponds to the sixteenth harmonic of C That is:
  • the waveshape amplitudes maybe computed using only those harmonics having a frequency below 12.9 kHz.
  • all sixteen Fourier components will be included in the amplitude computations for each note up to and including G
  • the sixteenth harmonic has a frequency below 12.9 kHz-
  • G #5 only fifteen Fourier components will be included in the amplitude computation, since the sixteenth harmonic has a frequency and C the amplitude computations will be limited to the harmonics indicated in Table I.
  • At C only six components will be employed to synthesize the wave shape, since the sixth harmonic has a frequency of 12.558 kHz and the seventh harmonic lies above 12.9
  • FIG. 1 is an electrical block diagram of a computer organ employing harmonic limiting.
  • FIG. 2 is an electrical block diagram of a first embodiment of theharmonic inhibit logic utilized in the computor organ of FIG. 1.
  • FIG. 3 shows typical musical waveshapes generated by a computor organ employing the harmonic inhibit logic of FIG. 2.
  • FIG. 4 is a timing diagram illustrating inhibition of the Fourier component calculations during generation of the musical waveshapes illustrated in FIG. 3.
  • FIG. 5 is an electrical block diagram of an alternative embodiment of the harmonic inhibit logic utilized by the computor organ of FIG. 1.
  • FIG. 6 shows typical musical waveshapes, generated using the harmonic inhibit logic of FIG. 5.
  • FIG. 7 is atimingdiagram illustrating harmonic limit ing in a polyphonic computor organ.
  • FIG. 8 is an electrical block diagram showing implementation of harmoniclimiting in a parallel processing computor organ.
  • the computor organ 10 of FIG. 1 operates to produce via a sound system 11a musical note selected by the keyboard switches 12. This is accomplished by calculating the discrete Fourier components associated with amplitudes at successive sample points of a waveshape characterizing the selected note. The components are algebraically summed in an accumulator 13 which, at the end of each computation time interval t, contains the amplitude at the current sample point. This amplitude is provided via a gate 14, enabled by the 1, signal on a line 15, to a digital-to-analog converter 16 which supplies to the sound system 11 a voltage corresponding to the waveshape amplitude just computed.
  • the waveshape amplitude X,,(qR) at each sample point is computed in accordance with the following discrete Fourier representation of a sampled periodic complex waveshape:
  • n l,2',3,..'.,L designates the Fourier component being evaluated.
  • n 1 corresponds to the fundamental
  • n 2 corresponds to the second harmonic
  • n 3 corresponds to the third harmonic
  • the harmonic coeffcient C specifies the relative amplitude of the respective n' Fourier component.
  • the value W designates the maximum number of Fourier components included in any amplitude computation by the organ 10.
  • W 16 16 harmonics
  • the number L specifies the number of Fourier components included in a specific amplitude computation. In accordance with the present invention, the number L will depend on which note is being generated.
  • the computor organ 10 of FIG. 1 implements equation 9 by computing the amplitude value X (qR) for each sample point during a time interval t,.
  • the individual harmonic component amplitudes F"" C, sin (qr/W) nqR for each of the L harmonic components are calculated separately during successive time intervals i established by a clock 21 and a counter 22.
  • the amplitude F of the first harmonic (n l) is calculated.
  • This value F is placed in the accumulator 13.
  • the amplitude F of the second Fourier component is computed and added to the accumulator 13 contents.
  • the third harmonic amplitude F" is calculated and added to the accumulator 16.
  • the number W of iterations of this routine is controlled by the harmonic inhibit logic 20 in cooperation with the counter 22.
  • the routine is terminated when all Fourier components associated with the particular amplitude computation have been evaluated. Upon such termination, the algebraic sum contained in the accumulator 13 will correspond to the amplitude I 6 for the sample point designated by the value qR.
  • the waveshape amplitude x (qR) in the accumulator '13 is gated to.-the digital-to-analog converter 16 at theend of the computation interval 1,.
  • the accumulator 13 then is cleared by the signal on the line 15, and computation of the amplitude at the next sample point subsequently is initiated.
  • the value qR is incremented and the L harmonic component amplitudes F are calculated for the sample point designated by the new value of qR.
  • the entire waveshape will be generated, the sound system 11 reproducing the musical note as the amplitude computations are carried out..
  • a note interval adder 23 contains the value qR identifying the sample point at which the waveshape amplitude currently is being evaluated. This value qR is incremented at the beginning of each computation interval t, by adding the selected frequency number R to the previous contents of the adder 23.
  • the selected value R is supplied to the adder 23 via I clock pulse of a new cycle, the current value qR contained in the note interval adder23 is entered into the harmonic interval adder 25 via a line 26 and a gate 27.
  • the value qR is added to the previous contents of the adder 25.
  • the harmonic interval adder 25 will contain the value nqR, where n 1,2,...L for the n order harmonic component concurrently being evaluated.
  • the harmonic interval adder 25 also is of modulo M.
  • An address decoder 28 accesses-from a sinusoid table 29 the value sin (iv/W) nqR corresponding to the argument nqR received via a line 30 from the harmonic interval adder 25.
  • the sinusoid table 29 may comprise a read only memory storing values of sin (Ir/W) (b for 0 i d) 2W at intervals of D, where D is called the resolution constant of the memory.
  • the value sin (1r/W) nqR, supplied via a line 31, is multiplied by the-coefficient C" for the corresponding rl" harmonic by a multiplier 32.
  • the multiplication product represents the amplitude F of the n'" harmonic component and is supplied via the line 33 to the accumulator 13.
  • the appropriate coefficient C is accessed from the harmonic coefficient memory 18 by an address control unit 34 advanced by timing signals received from the counter 22 via a line 35. Readout from the harmonic coefficient memory 18 is inhibited by the harmonic inhibit logic 20 for those higher order Fourier components not included in a particular amplitude computation. This is facilitated via an enable/inhibit signal line 36.
  • FIG. 2 shows illustrative circuitry 20A useful as the harmonic inhibit logic 20 of FIG. 1.
  • each waveshape amplitude computation is performed in a fixed time interval t regardless of how many Fourier components are included in that computation.
  • the interval t is established by the counter 22 which receives t pulses at the system clock rate f from the clock 21 via a line 37.
  • the counter 22 preferably is of modulo l6, and produces on the lines 350 35d a fourbit binary'signal designating the respective calculation timing pulses i through t As indicated by the tim- .logic 20A on the correspondingly designated line.
  • coding circuitry 40 including the OR gates 41 46 and a one-of-ten to binary encoder 47 provide on the lines 48a 48d a signal specifying in binary code the highest Fourier component (L) to be included in the waveshape amplitude computation for that note.
  • a flipflop 49 is set to l by the signal on the line 15.
  • the l" output of the flip-flop 49 functions as an enable signal on the line 36 to the harmonic coefficient memory 18.
  • the flip-flop 49 remains set to l the memory 18 is enabled, and calculation of the Fourier coefficients is not inhibited.
  • the computation pulses r t from the counter 22 are comparedwith the maximum harmonic designation signal (L) on the lines 48a 48d by a comparator 50.
  • a comparator 50 When coincidence occurs, indicating that the highest harmonic concurrently is being evaluated and that subsequent harmonics must be inhibited, an output signal is produced on the line 51 from the comparator 50.
  • the coincidence output signal from the comparator 50 resets the flip-flop 49 to This terminates the enable signal on the line 36 and inhibits subsequent readout from the harmonic coefficient memory 18.
  • the output of the harmonic coefficient memory 18 is zero.
  • the output F of the harmonic amplitude multiplier 32 likewise is zero. The higher harmonics effectively are inhibited.
  • the encoding circuitry 40 ofcourse is selected with reference to the highest harmonic (L) desired for each note being produced.
  • L the highest harmonic
  • the signals provided on the lines 48a 48d will correspond to the binary representation of the value L listed in that table.
  • the encoder 45 produces on the lines 48a 48d a signal L 15.
  • the comparator 50 will produce a coincidence output, thereby resetting the flip-flop 49 and inhibiting readout from the harmonic coefficient memory during the time t (see FIG. 4).
  • the sixteenth Fourier coefficient thus is not included in the amplitude computation.
  • the OR gate 46 provides an output on a line 55, causing the encoder 47 to provide on the lines 48a 48d the binary representation of the value L 6.
  • the comparator 50 then will cause the flip-flop 49 to be reset'to 0" v 8 after t thereby effectively inhibiting calculation of the seventh through 16th Fourier components. 7
  • the encoder circuitry 40 receives no input. Accordingly, the
  • the harmonic coefiicient memory 18 and the memory address control 34 advantageously are implemented using a commercially available integrated circuit read-only-memory (ROM) such as the Signetics type 8223.
  • ROM read-only-memory
  • This device includes address control circuitry which accepts a binary coded address like that provided on the lines 35, and automatically accesses I from the corresponding memory storage location a vword of up to eight bits.
  • the same integrated circuit includes memory output enable/inhibit circuitry controlled by a chip enable input to which the line 36 (FIG. 2) may be connected.
  • the actual .harmonic coefficient values stored in the memory 18 are of course a design choice which will depend on the desired tonal quality of the sound being produced by the organ 10.
  • Table II lists typical harmonic coefficient values C which will produce a diapason-type organ sound. 7
  • the one-of-ten 'to binary encoder 47 may comprise a conventional diode array having teninput lines and four, binary coded output lines. Such devices are shown in the standard text entitled Computer Logic by Ivan Flores, Prentice Hall, 1960 at Chapter 11.8.
  • the counter 22 may be implemented using a Signetics type 8280 four-bit binary counter contained in a single integrated circuit chip.
  • the comparator 50 may comprise a Signetics type 8269 integrated circuit four-bit comparator.
  • the encoding circuitry 40 may be eliminated.
  • the number L specifying the highest Fourier component to be computed for each note then may be stored in the memory 17 along with the corresponding frequency number R.
  • the associated L number will be accessed from the memory 17 and supplied via the lines 54a-54d directly to the comparator 50.
  • the logic 20A will function as just described to limit harmonic production.
  • the system clock rate f. may have the minimum phonic system).
  • the clock rate will be selected slightly higher than the minimum value, to provide a safety factor S greater than 1.000 for the Nyquist criteria.
  • this safety factor may be chosen to be slightly greater than 2 which is the interval between two adjacent tones in an equally tempered scale.
  • the safety factor may be selected as S I 2 1.082. Using this safety factor, the Nyquist frequency f-* and the clock rate f for a monophonic instrument system will be;
  • the clock 21 utilized with the logic 20A of FIG. 2 thus may have this frequency f,*.
  • the waveshape amplitudes will be computed at successive fixed time intervals 1, l/f so that the number of sample points per period of the generated note will be given by:
  • harmonic inhibit logic of FIG. 1 In this embodi- 81 cooperate to gate onto the buss 66 the timing sigment, the counter 2212 provides a separate output on one of the sixteen lines designated t through t for each of the corresponding calculation times.
  • the harmonic' coefficient memory 18b is implemented by a set of sixteen registers 61a 61p which store the respective harmonic coefficients C through C
  • the memory address control 34b readily isimplemented by a set of gates 62a 62p each associated with the corresponding register 61a 61p and operated by the respective signals t t received from the counter 22.
  • the gate 62a gates the coefficient C, from the register 61a via a buss 63 to the harmonic amplitude multiplier 32.
  • the harmonic inhibit logic 20B functions to reset the counter 22a after the highest desired Fourier component has been calculated. For example, if the key C is selected at the keyboard switches 12, the signal on the C line is supplied via an OR gate 64 to enable an AND gate 65. When the timing pulse 1 occurs, resulting in calculation of the sixth harmonic, the pulse r is gated via the AND gate 65 to a buss 66. After a delay of less than the time interval't provided by a delay circuit 67, the computation time interval pulse t, is generated. This resets the counter 22b and terminates the current waveshape amplitude computation. The seventh and higher Fourier components are not evaluated, and computation of the waveshape amplitude at the next sample point begins immediately. Eventually the waveshape C shown in FIG. 6 will be generated.
  • the duration t, taken to compute each amplitude sample point will not be a constant for all notes, but will depend 'on the number of Fourier components computed for each note.
  • the signal providedvia an OR gate 68 will en able an AND gate 69.
  • the signal t will be gated via the AND gate 69 onto the buss 66. This will cause termination of the amplitude computation cycle after evaluation of the first ten Fourier components, and immediately initiate computation of the next sample point amplitude.
  • the generated D #6 Waveform will have the appearance shown in FIG. 6. Note that for D #8 each sample point interval has a duration t, 101 whereas for the C waveshape, the duration t 6t
  • the various OR gates 70 74 and AND gates 75 nal t t appropriate for limiting harmonic generation for the selected note. I
  • the invention is not so limited. Harmonic limiting thus can advantageously be employed in a polyphonic system, such as that described in the above identified patent application entitled COMPUTOR ORGAN.
  • the waveshape amplitude supplied to the digital-toanalog converter is the sum of the separately computed amplitudes for each note of the chord being played. Such computation may be accomplished on a time sharing basis, as illustrated diagrammatically in FIG. 7 for a (K 3) polyphonic system in which three notes may be played simultaneously.
  • each fixed computation interval t includes three consecutive subintervals t,,, t,;, t during which the amplitudes for three notes are computed separately.
  • Each of these subintervals includes 16 shorter intervals t during which the individual Fourier components associated with the respective notes are calculated. For example, if the chord C E 6,, is played, the C amplitude may be computed during the interval t,, and the E and G amplitudes computed during the i and t intervals respectively.
  • Harmonic limiting of the type described herein then may be utilized independently during each subinterval I I t to inhibit calculation of harmonics above the respective L value for the selected notes.
  • the harmonic limiting circuitry will inhibit Fourier component calculation after evaluation of the L 12, L 9 and L 8 components respectively during the intervals t,, 1,, and t as indicated in FIG. 7.
  • FIG. 8 shows how harmonic limiting may be applied to a COMPUTOR ORGAN USING PARALLEL PRO- CESSING such as that shown in the above mentioned patent application Ser. No. 298,365.
  • the odd-valued Fourier components n 1,3,5,
  • the even harmonics n 2,4,6,
  • the individual components evaluated in the channels 91 and 92 are summed in an adder circuit 93 and supplied via a line 33' to an accumulator l3, digital-to-analog converter l6 and sound system 11 like that of FIG. 1.
  • Note selection is memory 17' which supplies the selected R numbers via a line 94 to bothprocessing channels 91, 92.
  • the memory 17' may contain the L number itself, or some other coded designation associated with this L number.
  • the designation code is supplied via a line 95 to a harmonic limit memory 96 advantageously implemented by a Signetics type 8223 integrated circuit read-only-memory or like device.
  • the designation code accomplished by keyboard or pedalswitches 12 cooperating with a frequency number.
  • the access control circuitry 96a causes the access control circuitry 96a to read out from the memory 96 the stored contents specifying the highest order odd (L,,,,,,,) and highest order even (L Fourier component to be calculated. These values are 5 supplied via the respective lines 97, 98 to'appropriate comparators 99, 100 associated with the respective processing channels 91, 92.
  • the comparator 99 compares the value L with a signal supplied via a line 101 indicating which component presently is being calculO lated in the channel 91.'Whe n coincidence is obtained,
  • an arbitrary designation code 0001 "' may be stored in thememory 17 together with the R numbers associated with the notes .C-,, B, and A
  • the code 0001 will be supplied to the memory access control 96a, causing readout. from a certain storage location in the memory 96.
  • This location advantageously contains the values L 5 and L 6. Accordingly, calculations in the channels 91 and 92 will be inhibited respectively 25 after evaluation of the 5" and 6" Fourier components,
  • 35 plitude being computed by individually calculating a set of constituent Fourier components of said waveshape, each Fourier component being calculated by multiplying a trigonometric function of the waveshape sample point by a harmonic coefficient value which esnent, said instrument providing a signal indicating which order Fourier component currently is being calculated, said calculated components beingcombined to obtain the waveshape amplitude at each sample point, musical notes being produced by converting said computed waveshape amplitudes for successive sample points to musical sounds as said computations are carried out, the improvement wherein said instrument includes note selection switches and harmonic inhibit logic for limiting the components in said set only to those having a frequency below a certain value within the normal human hearing range, said harmonic inhibit logic comprising:
  • circuitry providing, in response to switch selection of each note, a signal designating the highest order Fourier component to be calculated for that note,
  • a musical instrument for comparing said highe st-order- I designating signal and said order-indicating signal, and for providing an output when the compared signals are equal, inhibit circuitry for inhibiting calculation of higher order Fourier components in response tooccur- 2.
  • a musical instrument wherein said certain value is approximately 13 kHz, wherein.
  • a musical instrument according to claim 1 comprising:
  • a counter receiving said timing pulses t and establishing each amplitude computation regular time interval 1,, the count of said counter during each computation interval establishing which order Fourier component currently can be calculated by said instrument, said order-indicating signals being indicative of said count.
  • a musical instrument wherein said amplitudes are computed digitally and are converted by a digital-to-analog converter, wherein said computation interval 1 is of fixed duration regardless of which note is being produced, wherein said digitalto-analog conversion occurs at the end of each interval 2,, and wherein for notes having inhibited Fourier components, the uninhibited components are calculated in a time interval less than t,.
  • note selection means for accessing from said memory the frequency number associated with a selected note
  • harmonic inhibit logic operative upon detection by said comparator of coincidence between the valuesn and L, for inhibiting calculation by said evaluation circuitry of Fourier components of order higher than L.
  • a musical instrument according to claim 5 wherein said memory also stores a highest order harmonic designation code for eachnote, said harmonic inhibit logic being responsive to the designation code accessed from said memory together with said associated frequency number when a note is selected.
  • a musical instrument according to claim 7 further comprising a harmonic limit memory containing certain L designating values, said code causing access from said harmonic limit memory of the L designating value associated with the selected note.
  • a musical instrument according to claim 5 v wherein different subsets of said Fourier components are calculated concurrently in separate parallel processing channels, said harmonic inhibit logic being operable separately to limit the Fourier components computed by each processing channel.
  • a musical instrument including a clock for controlling the rate at which individual Fourier components are calculated by said evaluation circuitry, said rate being established by'the single highest frequency f,, of any uninhibited component included in the amplitude computation for any note, said rate being a multiple of the Nyquist frequency 2f,, times a safety factor S having a value greater than 1.000.
  • a musical instrument according to claim 12 wherein for a polyphonic instrument capable of simultaneously producing K notes, said multiple is K, and wherein for an instrument having P parallel processing channels, said multiple is III.
  • V n 1 I I
  • L signifies the number of Fourier components included in each amplitude computation for a particular note
  • W is the maximum number of components included in the computation for any note produced by said instrument
  • C is the coefficient of the corresponding n'" Fourier component
  • R is a number specifying the period of said waveshape
  • a keyboard including note selection switches, actuation of any keyboard switch causing access from said frequency number memory of the R value corresponding to the note selected by that actuated key,
  • the improvement wherein for each produced note the value L is such that all of the Fourier components included in the amplitude computation have frequencies below some preselected frequency within the human hearing range, said improvement comprising:
  • harmonic inhibit logic responsive to actuation of at least some keyboard switches for inhibiting said harmonic component evaluation circuitry from calculating F"" for those Fourier components of the note selected by said actuated switch which are higher in frequency than said preselected frequency.
  • a musical instrument wherein said frequency number memory stores values of R together with codes designating the value of L associated with each R value, and wherein actuation of each key causes access from said frequency number memory of the corresponding value R and of the L- designating code associated therewith, and
  • harmonic inhibit logic is responsive to efficients associated with Fourier components of order higher than L, thereby effectively preventing calculation by said evaluation circuitry of harmonics having frequencies above said preselected frequency.
  • harmonic component evaluation circuitry calculates all W Fourier components for each note unless inhibited
  • harmonic inhibit logic comprises circuitry for detecting coincidence between the value L designated by said code and a signal indicating which Fourier component currently is being calculated by said evaluation circuitry, said harmonic inhibit logic inhibiting readout "from said harmonic coefficient memory for the remainder of each amplitude computation interval after detection of such coincidence.
  • each waveshape amplitude is computed in a fixed time interval 1, regardless of which note is being produced, said instrument including a clock and a counter cooperating therewith to establish said intervals I and wherein said Fourier component indicating signal is derivedfrom the timing output of said clock and counter.
  • said evaluation circuitry provides a signal indicating which order Fourier component currently is being evaluated, said harmonic inhibit logic including;

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US3910150A (en) * 1974-01-11 1975-10-07 Nippon Musical Instruments Mfg Implementation of octave repeat in a computor organ
US3913442A (en) * 1974-05-16 1975-10-21 Nippon Musical Instruments Mfg Voicing for a computor organ
US3915047A (en) * 1974-01-02 1975-10-28 Ibm Apparatus for attaching a musical instrument to a computer
DE2524062A1 (de) * 1974-05-31 1975-12-11 Nippon Musical Instruments Mfg Elektronisches musikinstrument mit vibratoerzeugung
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US4224856A (en) * 1977-09-05 1980-09-30 Nippon Gakki Seizo Kabushiki Kaisha Waveshape memory type keyboard electronic musical instrument
US4246823A (en) * 1977-11-01 1981-01-27 Nippon Gakki Seizo Kabushiki Kaisha Waveshape generator for electronic musical instruments
US4265158A (en) * 1979-02-09 1981-05-05 Shuichi Takahashi Electronic musical instrument
US4338674A (en) * 1979-04-05 1982-07-06 Sony Corporation Digital waveform generating apparatus
US4343218A (en) * 1978-04-11 1982-08-10 Nippon Gakki Seizo Kabushiki Kaisha Electronic musical instrument
US4351219A (en) * 1980-09-25 1982-09-28 Kimball International, Inc. Digital tone generation system utilizing fixed duration time functions
US4352312A (en) * 1981-06-10 1982-10-05 Allen Organ Company Transient harmonic interpolator for an electronic musical instrument
US4444082A (en) * 1982-10-04 1984-04-24 Allen Organ Company Modified transient harmonic interpolator for an electronic musical instrument
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USRE31648E (en) * 1973-03-10 1984-08-21 Nippon Gakki Seizo Kabushiki Kaisha System for generating tone source waveshapes
US4811644A (en) * 1985-02-26 1989-03-14 Kabushiki Kaisha Kawai Gakki Seisakusho Electronic musical instrument for generation of inharmonic tones
US20060201312A1 (en) * 2003-03-28 2006-09-14 Carlo Zinato Method and electronic device used to synthesise the sound of church organ flue pipes by taking advantage of the physical modelling technique of acoustic instruments

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US4119005A (en) * 1973-03-10 1978-10-10 Nippon Gakki Seizo Kabushiki Kaisha System for generating tone source waveshapes
USRE31648E (en) * 1973-03-10 1984-08-21 Nippon Gakki Seizo Kabushiki Kaisha System for generating tone source waveshapes
US3888153A (en) * 1973-06-28 1975-06-10 Nippon Gakki Seiko Kk Anharmonic overtone generation in a computor organ
US3935781A (en) * 1973-08-03 1976-02-03 Nippon Gakki Seizo Kabushiki Kaisha Voice presetting system in electronic musical instruments
US3894463A (en) * 1973-11-26 1975-07-15 Canadian Patents Dev Digital tone generator
US3915047A (en) * 1974-01-02 1975-10-28 Ibm Apparatus for attaching a musical instrument to a computer
US3926088A (en) * 1974-01-02 1975-12-16 Ibm Apparatus for processing music as data
US3910150A (en) * 1974-01-11 1975-10-07 Nippon Musical Instruments Mfg Implementation of octave repeat in a computor organ
US3884108A (en) * 1974-01-11 1975-05-20 Nippon Musical Instruments Mfg Production of ensemble in a computor organ
US3908504A (en) * 1974-04-19 1975-09-30 Nippon Musical Instruments Mfg Harmonic modulation and loudness scaling in a computer organ
US3978755A (en) * 1974-04-23 1976-09-07 Allen Organ Company Frequency separator for digital musical instrument chorus effect
US3929053A (en) * 1974-04-29 1975-12-30 Nippon Musical Instruments Mfg Production of glide and portamento in an electronic musical instrument
US3913442A (en) * 1974-05-16 1975-10-21 Nippon Musical Instruments Mfg Voicing for a computor organ
DE2523881A1 (de) * 1974-05-31 1975-12-11 Nippon Musical Instruments Mfg Elektronisches musikinstrument mit rauschueberlagerungseffekt
DE2524062A1 (de) * 1974-05-31 1975-12-11 Nippon Musical Instruments Mfg Elektronisches musikinstrument mit vibratoerzeugung
US3935783A (en) * 1974-07-08 1976-02-03 The Wurlitzer Company Electronic piano circuit
US3956960A (en) * 1974-07-25 1976-05-18 Nippon Gakki Seizo Kabushiki Kaisha Formant filtering in a computor organ
US3982460A (en) * 1974-09-17 1976-09-28 Kabushiki Kaisha Kawai Gakki Seisakusho Musical-tone-waveform forming apparatus for an electronic musical instrument
US3951030A (en) * 1974-09-26 1976-04-20 Nippon Gakki Seizo Kabushiki Kaisha Implementation of delayed vibrato in a computor organ
US3972259A (en) * 1974-09-26 1976-08-03 Nippon Gakki Seizo Kabushiki Kaisha Production of pulse width modulation tonal effects in a computor organ
US3952623A (en) * 1974-11-12 1976-04-27 Nippon Gakki Seizo Kabushiki Kaisha Digital timing system for an electronic musical instrument
US4048480A (en) * 1975-04-30 1977-09-13 Minot Pierre J M Generators of anharmonic binary sequences
FR2321161A1 (fr) * 1975-08-11 1977-03-11 Deutsch Res Lab Synthetiseur de sons polyphonique
US4202234A (en) * 1976-04-28 1980-05-13 National Research Development Corporation Digital generator for musical notes
US4177706A (en) * 1976-09-08 1979-12-11 Greenberger Alan J Digital real time music synthesizer
US4177708A (en) * 1977-06-17 1979-12-11 Rochelle Pinz Combined computer and recorder for musical sound reproduction
US4224856A (en) * 1977-09-05 1980-09-30 Nippon Gakki Seizo Kabushiki Kaisha Waveshape memory type keyboard electronic musical instrument
US4246823A (en) * 1977-11-01 1981-01-27 Nippon Gakki Seizo Kabushiki Kaisha Waveshape generator for electronic musical instruments
US4343218A (en) * 1978-04-11 1982-08-10 Nippon Gakki Seizo Kabushiki Kaisha Electronic musical instrument
US4192210A (en) * 1978-06-22 1980-03-11 Kawai Musical Instrument Mfg. Co. Ltd. Formant filter synthesizer for an electronic musical instrument
US4211138A (en) * 1978-06-22 1980-07-08 Kawai Musical Instrument Mfg. Co., Ltd. Harmonic formant filter for an electronic musical instrument
US4265158A (en) * 1979-02-09 1981-05-05 Shuichi Takahashi Electronic musical instrument
US4338674A (en) * 1979-04-05 1982-07-06 Sony Corporation Digital waveform generating apparatus
US4446770A (en) * 1980-09-25 1984-05-08 Kimball International, Inc. Digital tone generation system utilizing fixed duration time functions
US4351219A (en) * 1980-09-25 1982-09-28 Kimball International, Inc. Digital tone generation system utilizing fixed duration time functions
US4352312A (en) * 1981-06-10 1982-10-05 Allen Organ Company Transient harmonic interpolator for an electronic musical instrument
US4444082A (en) * 1982-10-04 1984-04-24 Allen Organ Company Modified transient harmonic interpolator for an electronic musical instrument
US4811644A (en) * 1985-02-26 1989-03-14 Kabushiki Kaisha Kawai Gakki Seisakusho Electronic musical instrument for generation of inharmonic tones
US20060201312A1 (en) * 2003-03-28 2006-09-14 Carlo Zinato Method and electronic device used to synthesise the sound of church organ flue pipes by taking advantage of the physical modelling technique of acoustic instruments
US7442869B2 (en) * 2003-03-28 2008-10-28 Viscount International S.P.A. Method and electronic device used to synthesise the sound of church organ flue pipes by taking advantage of the physical modeling technique of acoustic instruments

Also Published As

Publication number Publication date
DE2362050C3 (de) 1985-02-21
JPS4993010A (ja) 1974-09-04
JPS5236694B2 (ja) 1977-09-17
DE2362050B2 (de) 1980-04-24
DE2362050A1 (de) 1974-06-27

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