JPS6115435B2 - - Google Patents

Description

[Detailed description of the invention]

The inventor of the present invention has already proposed an automatic rhythm performance device that is capable of irregularly selecting different rhythm patterns for short periods of time in order to obtain an impromptu performance effect. The device allows improvisational performance, but even if the main melody is in triplet, for example, it makes irregular choices just as it does in other types, so Sometimes we want to change the irregularity so that there are more patterns. Conventional devices have not been able to satisfy this desire. SUMMARY OF THE INVENTION An object of the present invention is to provide a random rhythm pattern generation circuit that can generate irregularly selected rhythm patterns and change the irregularity. Embodiments of the present invention shown in the drawings will be described below. In the block diagram shown in Fig. 1, 1-1,
It is assumed that 1-2 and 1-3 are pulse generating circuits which have different oscillation frequencies and whose frequency ratio is not an integer. 2-1 and 2-2 are pulse occupancy rate variable circuits such as monostable multivibrators, and one or more are provided for each pulse generation circuit output. Provided for output. Reference numerals 3-1, 3-2, and 3-3 are latch circuits that use delay type flip-flops, for example, to connect the output pulses of the pulse generation circuit 1-2 and the output pulses of the pulse occupancy rate variable circuits 2-1 and 2-2. is received as data. 4 is a decoder which receives and decodes the output of the latch circuit as a multi-bit binary code. 5
is a rhythm pattern generation circuit that stores a large number of rhythm patterns in a read-only memory (ROM).The output of the decoder 4 is used as one address, and the output of the pulse generation circuit 8 is read out sequentially as the other address. applied to circuit 9. Reference numeral 6 indicates a main clock pulse generation circuit, and reference numeral 7 indicates a frequency dividing circuit. For example, the pulse generation circuit 1-1 etc. has a pulse occupancy rate of 50%, and this is connected to the monostable multivibrator 2-
1 and 2-2 to change the occupancy to 80%. This is done by adjusting the variable resistor VR (and) or the capacitor C for adjusting the oscillation time of the monostable multivibrator MMV, as shown in FIG. Since the latch circuit 3-1 uses a delay type flip-flop in this case, it latches when the data input is "H" at the rising edge of the clock pulse from the frequency divider circuit 7.
The Q terminal is set to "H". If the input is "L", it will not be latched. Pulse generation circuit 1-1
If the pulse repetition frequency and the clock pulse repetition frequency are selected to be a non-integer ratio, it is so irregular that it is impossible to predict whether the data input from the pulse generation circuit will be latched or not. Therefore, the output of the latch circuit is
In this case, if the decoder 4 decodes the code as a 3-bit code, the output of the decoder will be 8, shown as 11 to 18.
Select connecting lines of books irregularly. The rhythm pattern generation circuit 5 performs the selection and sequential pulse generation circuit 8.
Since the readout address is determined by the pulses from the rhythm pattern generation circuit 5, the pattern stored in the rhythm pattern generation circuit 5 can be extracted as a musical tone in the tone generator circuit 9. If we examine the decoding status in the decoder 4 using 3-bit input, we will see the following table.

[Table] When _Q1 is “0”, the output lines that are addressed are lines 11, 13, 15, and 17, and vice versa.
When Q ₁ is "1", they are 12, 14, 16, and 18. Also, when Q ₃ is “0”, the specified output line is 1
1 to 14, and 15 to 18 when Q ₃ is "1". By changing the occupancy rate of the pulses applied to the data input of the delay type flip-flop, the probability of whether the output Q becomes "1" or "0" changes. If the output of the variable pulse occupancy rate circuit 2-1 is a pulse in which the "H" state is longer than the "L" state, one of the even-numbered output lines 12, 14, 16, and 18 is selected more often. On the other hand, when "L" becomes longer, more output lines of the inverse number are selected. If the output of the variable occupancy rate circuit 2-2 is further lengthened, either 16 or 18 will be selected. Therefore, if the sliding terminal of the variable resistor of the variable occupancy rate circuit is changed from the center to one end to the other end,
Since the lengths of the "H" and "L" outputs change, the rhythm pattern selection changes. Therefore, the rhythm that you want to increase the number of repetitions (for example, a rough triplet) is stored in the rhythm pattern generation circuit 5 in correspondence with the output lines 16 and 18, and the pulse occupancy rate variable circuit 2-1 etc. The variable resistor sliding terminal may be moved to one end to increase the ratio. On the other hand, if the variable resistor sliding terminal is moved to the other end, the output lines become 12 and 14 so that, for example, a thin triplet is selected many times. Note that if the sliding terminal of the variable resistor of the variable pulse occupancy rate circuit is placed in the center, the selection of the rhythm pattern will be performed completely irregularly. In this way, according to the present invention, a specific pattern can be selected more times than other patterns by changing the occupancy rate of the pulses when reading patterns stored in advance in the rhythm pattern generation circuit. This allows the player to consciously change the irregular selection of rhythm patterns and the selection of more specific patterns, which greatly contributes to improving performance effects. For example, when the tempo of the main performance melody is slow or fast, it is easy to select accompaniment rhythms many times.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a diagram showing a pulse occupancy rate variable circuit in FIG. 1-1, 1-2, 1-3...pulse generation circuit,
2-1, 2-2...Pulse occupancy variable circuit, 3-
1, 3-2, 3-3... Latch circuit, 4... Decoder, 5... Rhythm pattern generation circuit, 6... Main clock pulse generation circuit, 7... Frequency divider circuit, 8...
Sequential pulse generation circuit, 9... sound source circuit.

Claims (1)

[Claims] 1. A rhythm pattern generation circuit that stores a plurality of rhythm patterns, a readout circuit that generates a readout clock pulse for reading rhythm patterns from the rhythm pattern generation circuit, and oscillation frequencies that are different from each other. at least one of the outputs of the pulse generation circuits;
a pulse occupancy rate variable circuit that changes the occupancy rate of one pulse; a latch circuit that latches the output pulse of the pulse generation circuit and the output pulse of the occupancy rate change circuit by a clock pulse from the readout circuit; A random rhythm pattern generation circuit comprising: a decoder that receives the output of the latch circuit as a multi-bit binary code and selects one of the plurality of rhythm patterns of the rhythm pattern generation circuit. .