US2142591A - Recorded music pitch and tempo adjustment indicating device - Google Patents

Description

Jan. 3, 1939. K, R055 2,142,591

RECORDED rmsm PITCH AND TEMPO ADJUSTMENT mmcmme DEVICE Filed Aug. 16, 19:7

QJNYENTORQ BY hmq -libs-s ATTORNEY.

Patented Jan. 3, 1939 1 TED s'riirss PATEN OFFICE INDICATING' DEVICE RECORDED MUSIC PITCH AND TEMPO AD- JUSTMENT liingltoss, Jackson Heights, Long Island, N. Y. Application August 16, 1937, Serial No. 159,256

5Claims.

The purpose oi'this invention is to provide an improvement in phonograph records, in which the speed at which the record is reproduced may be set to correspond with the speed at which 5 the record traveled when made, and in which -means is provided for determining the exact instant at which the record will start to play.

Theinventio'n is a phonograph record oi'the conventional type having additional grooves in which a constant frequency is recorded, and also --means:in the starting groove for producing beats atregular intervals before the record starts to 7 .25 must revolve to reproduce themusic'at the same Ditch that it was originaliy'recorded.

To provide means andapparatus to aurally indicate by comparison to a tuning fork, or-

specifically pitchedn'ote sounded on any musical so, instrument, the speed at which a phonograph record was recorded, whereby, with this knowledge, the speed of the reproducing machine may be" adjusted "to reproduce the recorded music at the proper pitch. v 35 To provide means and apparatus to indicate the tempo at which a musical composition was originally recorded.

To provide means and apparatus for recording a sub-audible frequency with relatively high am- 40 plitude peaks of relatively short duration at each cycle, these peaks being audible.

To provide means and-apparatus i'orre'cording a remilarly recurring click or beat which corresponds to the tempo or meter of the.com-

{a position recorded,

To provide means and apparatus for adjusting the speed of a phonograph record so that reproduced indicating tempo clicks are of the same frequency they were originally recorded.

so To means and method whereby, upon reproducing a phonograph record, the exact moment at which the recorded music will. begin can be -anticipated. To provide'means and 'apparatus.whereby a ll phonographjreccrd may be tuned so that-the nously controlled motors.

reproduced music will be played at the same pitch as it was originally recorded, thereby allowing a musician to play his instrument along with the reproduced music, and in exact pitch with aforesaid music.

To provide means and apparatus whereby a' musician may. turn a phonograph record to the pitch of his instrument. automatically causing recorded tempo beats to become reproducible,

so that the musician may know in advance, that, 10 upon reproducing said record, he may know the exact moment at which the recorded music will start, and that he will, upon playing his instru- I ment along with the recorded music, be in ex-' act tune with it. 16

To provide a pitch indicating device upon a phonograph record. To provide a tempo indicating device upon a phonograph recdrd.

. To provide a pitch and tempo indicatingde- 20 vice upon a phonograph record.

To provide means and apparatus whereby a listener of a phonograph record may adjust his phonograph turntable, independently of the speed marker upon the motor governor, so that a recorded symphony or other recorded music will be reproduced in proper pitch.

With these ends in view the invention embodies a phonograph record having an extended -starting groove, with means producing regular beats therein before the .record starts to play,

and additional center grooves recorded at regular frequency corresponding with the speed at which the record was made.

The drawing shows a plan view of a record embodying these features. It may be readily appreciated that present dayphonograph recording apparatus may be adjusted. accurately to a standard speed; This is generally done with a synchronousmotor or synchro The turntablespeed generally adopted is 78 revolutions per minute. To reproduce the finished records so that-the music is played at exactly the same-pitch aswas- 45,

recorded. it is necessary that the reproducing turntable revolve at exactly the same number of revolutions per minute as the recording turntable revolved when the music was originally recorded.

Nowyif a synchronous rcprod cing motor is geared to the same speed, say 7 R. P. M., as the recording turntable. the music will automatically be-reproduced at the same pitch. But in using any other type oi reproducing turntable vmotor, which usually has a speed control lever,

7 And also should the reproduction turntable turn at 77 instead of '78, the equation wouldbecome:

e 78n=33880 a==434.3

the playing of musicians who wish Federation of Musicians pitch at. which itwas recorded.

. There is, at present, no convenient way of adjusting the speed positively. Although there are etched marks on an indicating plate, which is generally set under a pointer on the speed control lever, the marxings (indicating revoluare more or less arbitrary, and

My invention is primarily intended for musiclans who either desire to play their own instrument along with the reproduced music. or who wish to be sure they are played in proper pitch.

It is also intended for music students or other to use my invention upon which patent is now pending, Serial Number 156,303, which consists of a phonograph record upon. which the accompaniment only is recorded. Since, in one form of this invention above mentioned, student exercises are harmonized, this accompaniment being recorded upon the phonoit is absolutely necessary that the at the identical speed graph disc, reproduction be eifected at which it was recorded.

As an example of the relation of turntable speed to the musical pitch, allow me to illustrate with an equation: A440 is the standard pitch adopted by the United States Government in 1920, and also the oiiicial pitch of the American since 1917. If A440 is recorded at 7'8 R. P. M., and reproduced at 79 R. P. M., the equation will become:---

,So, as will be seen, the recorded A440 wil become upon reproduction A445.

Since French pitch is A435, and this reproduced A4343 is even lower, the difference would be immediately noticeable by a musician, .and especially if he were to attempt to play along with the reproduced music.

Another feature of my invention is the way in which the tempo or meter of the recorded music is indicated in advance, so that a student, about to play an exercise or study along with the recorded accompaniment, may know the exact time to begin playing.

Numeral l indicates a phonograph record disc containing upon and within its surface a spiral groove having recorded thereupon, and therein, music, recorded in to the art. Numeral 2 indicates the entrance to the initial spiral groove, shown here as being the outermost groove. In some recordings this initial groove is the innermost, ,the phonograph reproducer traveling then from inside to outside. But, as I have shown, the phonograph reproducer,

travel from the outside toward the center during the record. The turntable and record in this instance will revolve clockwise. The reproducer needle will first encounter the at a constant rate, and

listening to the music.

the manner commonly known irregularity shown at I, which irregularity will cause a click to be reproduced, at 4 another click is produced, another at 0, and still another click will be produced at 6. At 1 the recorded musical composition will begin. The angular or radial separation between the irregularities I, l, 5, 0, and the point I where the recorded music will commence to be reproduced, is equal.

As will be seen, when the record is revolving the reproducing needle is following the groove starting at entrance 2, there will be, in this case, four evenly measured .clicks produced by irregularities 3, 4, 5, and B,

' at the exact point where the recorded music begins.

The grooves as followed by the needle from the beginning of the recorded music 1, to a point between I and 8, constitute the body of the record; the musical subject matter. At I is shown the customary more rapid spiral for the purpose of carrying the reproducer to a concentric groove near the center of the record. This is normally for the purpose of causing the reproducer, in its more rapid rate of travel at that point. to actuate an automatic motor cut-of! of some common type, and is known to the art.

At numeral 9 is shown a separate spiral, not essentially connected to the main grooves which are indicated as lying between points 2 and 8. This separate spiral 9 consists of several turns of a spiral, and is shown in the drawing as terminating in a concentric groove in. In this spiral I have recorded a constant frequency, A440 for example, and this A440. having been recorded upon the master, and having been used also as a reference to which the musicians, who played for the recording, tuned their instruments, this inner spiral, starting at 8, will upon reproduction sound the master tuning note' of the recorded music.

may speed up or slow down the turntable speed until unison between the reproduced frequency and the tuning fork is effected. when this is done, the reproduced music automatically will be played in proper pitch, and the four initial clicks or beats will occur-in, the correct time intervals.

It will be appreciated that I may choose any frequency as=a standard, and synchronism may be effected by comparison to a tuning fork of the frequency chosen, although, since the United States Government and American Federation of Musicians have ofll'cially adopted A440 as a standard, I prefer to use this frequency.

The use of the fork may be obviated where the musician's instrument may be above or below this standard, in which case he will sound the A, or tuning note, on his instrument, and

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