Casio Computer Co., Ltd.

Mayumi Ino

Junichi Minamitaka

Kunio Sato

An apparatus for producing a chord progression by connecting or chaining chord patterns. In a preferred embodiment, the apparatus includes as a source of musical knowledge, a database of musical structure of various music pieces and a database of chord patterns. In operation, from the musical structure database, a multi-leveled structural feature of a music piece is selected and determined level by level, either automatically, semi-automatically, or manually, through a dialogue conducted between the apparatus and the user. Thereafter, chord patterns are chosen one at a time from the chord pattern database in a similar dialogue manner. A concatenating module controls the concatenation of the chosen chord patterns to be commensurate with the characteristic musical structure previously determined, thereby to provide a chord progression with musicality, naturalness and well-balanced unity and variety. The produced chord progression may be utilized as a musical material from which an automatic composer synthesizes a melody of a music piece.

Apparatus for producing a chord progression by connecting chord patterns

A system for automatically determining principal tones of an accompaniment line supporting a melodic line comprises a plurality of principal tone inference engines which after principal tones in accordance with different rules of inference from one another and a priority control which controls priorities among the plurality of inference engines to determine final principal tones in the accompaniment line. Each principal tone inference engine may include a condition checker which checks to see whether musical conditions are met and a principal tone generator which generates principal tones. The priority control monitors the information supplied from the condition checkers to select final principal tones supplied from the principal tone generators. Some of the final principal tones may be dependent from the preceding principal tone while some others may be independent. There may be also be provided a storage of the structure of music which is reflected in a series of the final principal tones. In an application, a melodic line monitor is provided so that an accompaniment line interacting with the melody will be generated.

Accompaniment line principal tone determination system

An envelope extracting circuit extracts an envelope from the waveform sampled by a musical tone sampling circuit, and stores the envelope data into a memory. An envelope approximating circuit approximates the envelope data as stored in the memory by the function data such as linear or exponential function data. The original envelope is approximated by a limited number of function waveforms whose characteristics change at switching points.

Apparatus for extracting envelope data from an input waveform signal and

A system for automatically determining principal tones of an accompaniment line supporting a melodic line comprises a plurality of principal tone inference engines which infer principal tones in accordance with different rules of inference from one another and a priority control which controls priorities among the plurality of inference engines to determine final principal tones in the accompaniment line. Each principal tone inference engine may include a condition checker which checks to see whether muscial conditions are met and a principal tone generator which generates principal tones. The priority control monitors the information supplied from the condition checkers to select final principal tones supplied from the principal tone generators. Some of the final principal tones may be dependent from the preceding principal tone while some others may be independent. There may also be provided a storage of the structure of music which is reflected in a series of the final principal tones. In an application, a melodic line monitor is provided so that an accompaniment line interacting with the melody will be generated.

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Akishima, Japan

Mayumi Ino