The speed of rhythms in live acoustic music, literally the velocity at which notes are sounding, can be defined in absolute terms based on clock time. But there is also the perceived speed that, in the simplest terms, states that musical material can seem fast, slow or some other relational quality.
Speed is articulated by sounding rhythm. Rhythms, however, manifest themselves through a myriad of various implicit and explicit frames, depending on the musical context, including tuplets, meters (traditional and "irrational"), tempo, polytempos, pulses, polypulses, polyrhythms (superimposed frames), additive frames, divisive frames, metric modulation, time brackets and other structures. Through analysis and composition this PhD will research the current practice, precise identities and possibilities of the various time frames in music and the bearing they have individually and in combinations on the speed of the music.