Abstract:

The concept of ``groove,'' a musical element particularly operative in African-derived musics such as jazz, may be described as a collectively determined and relatively isochronous pulse that can be inferred from the interaction of a number of interlocking rhythmic groups. A powerful representation for musical rhythm as it appears in groove-oriented contexts has been developed. Implemented in the MAX music-programming environment, the representation encompasses pitch, accent, rhythmic deviations, tempo variation, note durations, and probabilistic processes. The design facilitates ``bottom-up'' combination techniques such as the construction of large musical objects by assembling small musical ``cells'' in series or parallel, and thus it allows improvisatory manipulation of simple rhythmic structures. The richness of control over many meaningful musical quantities distinguishes the representation from those in more common usage, such as music notation programs, sequencers, and drum machines. The implementation supports a variety of creative applications in improvised performance. Rather than attempting to make the system ``sound human'' by forcing it to simulate specific human activities, two alternative approaches are taken: the development of novel, sensitive control structures, and/or the emphasis on the system's active role as a situated participant in an interactive musical environment.