Supporting arbitrary beat patterns in chord-based note sequence generation

摘要

A performance engine selects note patterns from a pattern style containing a plurality of note patterns. The note patterns are categorized by embellishment type and by ranges of playback levels. In addition, a beat pattern is specified for each note pattern, indicating the chord rhythm with which the style can be used. The beat pattern is a bit array, with bits corresponding to every beat of one or more contiguous measures. In response to selection of a particular embellishment type and playback level, the performance engine selects a note pattern that meets the following qualifications: (a) it is of the selected embellishment type; (b) its designated range of playback levels includes the selected playback level; and (c) its beat pattern indicates that it can accommodate chord changes at the beats at which such changes occur in the currently selected chord progression. If there are no qualifying note patterns, these conditions are gradually relaxed until at least one of the note patterns qualifies.