Abstract: A system for use in an electronic musical instrument, which system includes a musical sound generating unit for generating a musical sound, and a detection unit for detecting that the magnitude of the musical sound data generated by the musical sound generating unit exceeds a processing capability, on the basis that the value indicated by the most significant bit prior to data processing not equal to that after data processing. A maintaining unit is also included which forcibly maintain the level of a signal representing the musical sound data at a maximum amplitude thereof, on the basis of the result of the detection effected by detection unit.

Abstract: According to the invention, elapsed time data indicative of a lapse of time are converted to greater values for permitting automatic performance according to the converted time data. Thus, it is made necessary, during fast forward of an automatic performance, only to convert the elapsed time data or time information of automatic performance information. In addition, the elapsed time data are converted into data, the value of which is reduced progressively with the lapse of time at a rate greater than the rate of change in the elapsed time data, for permitting automatic performance according to this data. Thus, it is made necessary, during rewind of an automatic performance, only to convert the elapsed time data or the time information of automatic performance information.

Abstract: According to the invention, a pedal operation is permitted independently for each group in a keyboard, and thus various ways of sounding musical tones can be realized. More specifically, a plurality of designation elements for designating the sounding of musical tones are divided into a plurality of groups, which are designated, and according to the group designation a musical control by a pedal operation is permitted independently for each group. Thus, a choice of a musical control by a pedal operation can be made for each group according to the group designation, thus permitting various ways of sounding musical tones.

Abstract: An input data processor selects a value indicated by change border data, and uses this value as a reference value for determining whether a predetermined process is effected, and to change the currently used value indicated by the change border data to another value when the value of the input data becomes equal to a predetermined value. Namely, when the value of the input data is in the vicinity of a specific value, the detection of a change of the input data can be effected by using a resolution smaller than another resolution used for the detection when the value of the input data is not in the vicinity of the specific value. Detection of a change of the input data can be efficiently performed.

Abstract: A device for use in an electronic musical instrument, in which data representing musical factors such as a tempo, a pitch and a timbre are changed at each repetition of an automatic performance, to thereby automatically effect variable automatic performances. Further, data representing a chord type and a chord root are input by a character-data input device such as a ten-key pad, and thus a chord input operation is facilitated, and moreover, a complicated finger manipulation becomes unnecessary. Furthermore, data representing chord types is input by at least one of the pitch input devices, and data representing chord roots is input by at least one of the other pitch input devices, and thus a chord performance is facilitated.

Abstract: A parameter signal generator including a parameter generating information storing unit for storing parameter generating information necessary for generating a parameter signal, and a parameter signal generating unit for generating a parameter signal. The parameter generating information is serially read from the parameter generating information storing unit and the thus-read parameter generating information is preset in a parameter signal generating unit other than the parameter generating information storing unit. Therefore, the parameter signal generator includes a storing unit other than the parameter signal generating unit, and accordingly, a general-use memory can be employed as the storing unit, to substantially lower cost. The processing of generating and radiating musical sounds can be performed at a practically required speed by employing a high speed processor as a central processing unit.

Abstract: A device for generating a waveform of a musical tone, which comprises a waveform data memory for storing data representing the waveforms of a plurality of musical tones, a waveform data selector for selecting any combination of more than two waveform data stored in the waveform data memory, a sound emission instructing unit for issuing an instruction for emitting a musical tone, a waveform data reading unit for reading out the waveform data selected by the waveform data selector from the waveform data memory in a reading step of a processing program common to the musical tones, in response to an instruction issued by the sound emission instructing unit by effecting a time sharing processing, and a synthesizing unit for accumulating and synthesizing the waveform data read out by the waveform data reading unit.

Abstract: A waveform data storing unit stores waveform data only at steps midway among a top zero level step and originally sampled steps at every sampling period from the top zero level step. An output means is included for outputting the waveform data at a moment staggered from another moment, at which the waveform data at the top zero level step and the originally sampled steps are ordinarily read out, by a period of time corresponding to half a step. The occurrence of a difference in phase of the read-out waveform is prevented without the need of a data correction unit. The waveform data storing unit stores midway-step data which are averages of waveform data at adjoining originally sampled steps and difference data representing the difference between the waveform data at the originally sampled steps and the midway-step data. A fine waveform can therefore be obtained while using a smaller quantity of data.

Abstract: A device for detecting data of contents of accompaniment for use in an electronic musical instrument in which the detection of data representing contents of a bass accompaniment is effected independently of the detection of data representing contents of a chord accompaniment, by separately providing a first portion for indicating pitches composing a chord to be performed and a second portion for indicating the lowest pitch of a bass accompaniment pattern in a pitch indicating unit and detecting pitches indicated in the second portion. Thus, data representing contents of a bass accompaniment and data representing contents of a chord accompaniment can be separately detected, whereby the electronic musical instrument can perform a bass accompaniment independent of a chord accompaniment, and thus the variety of a performance can be increased.

Abstract: A motif performing apparatus for use in an electronic musical instrument, which effects an automatic performance of a motif only while sounds are being radiated. The motif performing apparatus is able to store information representing motifs to be played, and to read and output information representing each of the motifs, separately, while instruction units for instructing a radiation of musical sounds are operated. Accordingly, even if the operation of an instruction unit is unchanged, the performance is varied according to a pattern of the information. Further, as long as the instruction unit is operated, a plurality of musical sounds are generated automatically and sequentially according to the pattern of the information, and thus a performance can be easily effected.

Abstract: A device for changing and controlling the rate of generating waveform data wherein rate changing data such as phase angle step data corresponding to steps, wherein each pair of contiguous steps has an interval smaller than a preset interval, are necessary. The necessary rate changing data of interval other than the preset rate changing data is obtained by effecting an interpolation from the preset rate changing data. Accordingly, it becomes unnecessary to store the rate changing data obtained by performing the interpolation, and thus, the quantity of the phase angle step data SD to the stored can be greatly reduced.

Abstract: A tone pitch changing device comprising an operation content memory for storing the contents of an operation required for generating a sound having a pitch which belongs to one of a group of pitches, a frequency interval between each pair of adjacent pitches of each group being different among the groups of pitches, a group selecting unit for selecting and indicating one of the groups of pitches, an operation content reading unit for reading the contents of an operation, required for generating a sound having a pitch of the group selected and indicated by the group selecting unit, from the operation content storing unit, an operating unit for performing an operation in accordance with the contents of the operation read from the operation content reading unit, an operation result memory for storing the result of the operation performed by the operating unit, a pitch indicating unit for indicating a pitch of the group, and an operation result reading unit for reading the result of the operation performed with r

Abstract: A method of performing an operational expression representing an operation on first and second operands used for computing various problem data and information relating to musical tones, the method comprising the step of representing problem data, which are to be processed, by using a representation system by which the first and second operands have the same sign, and by which the value of one of the first and second operands represented by bits having orders higher than those of bits used for representing the other of the operands is reduced by effecting a suppressing operation by using a suppressing parameter having a value larger than the value that can be obtained by the one of the first and second operands represented by the higher-order bits and the value of which is to be reduced, the step of computing mantissa part data of the thus represented problem data in accordance with power part data of the thus represented problem data, and the step of performing an carry operation if a carry is generated in t

Abstract: An envelope generator for use in an electronic musical instrument comprises a musical tone data processing unit to evaluate a rate of change in a current value of musical tone envelope data with respect to a target value based on a parameter, a changing rate control unit for decrementing a change in the current value such that the current value becomes closer to the target value, a detection unit to detect whether or not the rate of change becomes equal to 0, and a processing control unit control for stopping the evaluation the current value in response to a result of the detection.

Abstract: An electronic musical instrument with a channel assigning device which includes a characteristic information generating unit for generating characteristic information of musical tone envelopes, a sound radiation instructing unit for generating each musical tone selected by a musical tone selecting unit, a processing unit for processing the characteristic information generated by the characteristic information generating unit in response to an elapse of time and an assigned channel determining unit for comparing the results of the processing performed by the processing unit and determining a channel to which the musical tone information should be assigned in response to a sound radiation instruction from the sound radiation instructing unit.

Abstract: A channel assigning system which divides musical tone generating channels into a plurality of channel division areas and assigns musical tone generating channels of each channel division area to musical tones, in an ascending order of a value of a weighting factor corresponding to each musical tone generating channel, by searching for a musical tone channel corresponding to the smallest value of the weighting factor. Alternatively, the channel assigning system assigns musical tones in a descending order of a value of a weighting factor corresponding to each musical tone generating channel, by searching for a musical tone channel corresponding to the largest value of the weighting factor.

Abstract: A device for correcting a timing of music playing information including a determining unit and a correcting unit, the correcting unit corrects the timing of the change of the performance of a piece of music, which is outside the range of short time data, to a timing within the range of the short time data, in response to a determination by the determining unit.