In music, a time scale is specification of divisions (scale) of time or rhythm. Curtis Roads (2001, p.3-4) distinguishes nine time scales of music:
- Infinite: literally infinite, such as the length of sine waves in classical Fourier analysis,
- Supra: months, years, decades, and centuries; everything above the level of
- Macro: "overall musical architecture or form" or the level of the individual piece; minutes, hours, or even days,
- Meso: "Divisions of form" including movements, sections, phrases; seconds and minutes,
- Sound object (Schaeffer 1959, 1977): "a basic unit of musical structure" and a generalization of note (Xenakis' ministructural time scale); fraction of a second to several seconds,
- Micro: "sound particles" (see granular synthesis) down to the threshold of audible perception; thousands to millionths of seconds,
- Sample: sample (music), measured as are samples in millionths of a second or microseconds,
- Subsample: changes "too brief to properly recorded or perceived", billionths of a second, nanosecond, or less, and
- Infinitesimal: literally "infinitely brief" such as delta functions.
Music may, however, exist "outside" of time when structured through "principles whose defnitions does not imply a temporal order", including scales and many other precompositional techniques, musical instruments, and aleatoric music. Examples such as sound installations in which the order of the sound is determined by, for example, a listeners movement through the system, are thus placed in time. (ibid, p.38)
Source
- Roads, Curtis (2001). Microsound. MIT. ISBN 0-262-18215-7.
