In music, a pulse is a series of identical, yet distinct periodic short-duration stimuli perceived as points in time (DeLone et. al. (Eds.), 1975, chap. 3). Ideally, this is opposed to a series of identical but aperiodically occurring stimuli, a series of periodically occurring yet otherwise differentiated stimuli, or an uninterrupted stream of sound (such as a drone). A pulse may be an unheard event underlining a piece or metric level, thus the tempo of the piece is how fast the pulse is running, implied by the performer or listener based on context or past experience, or audible such as in Terry Riley's In C. Music is an art, entertainment, or other human activity that involves organized and audible sounds and silence. ... Periodicity is the quality of occurring at regular intervals (e. ... In physiology, a stimulus is a detectable change in the internal or external environment. ... A pocket watch, a device used to measure time. ... In music, a drone is a harmonic or monophonic effect or accompaniment where a note or chord is continuously sounded throughout much or all of a piece, sustained or repeated, and most often establishing a tonality upon which the rest of the piece is built. ... See: International System of Units, colloquially called the Metric System, and also metrication. ... In musical terminology, tempo (Italian for time) is the speed or pace of a given piece. ... Terry Riley – (Portrait by Betty Freeman) Terry Riley (born 24 June 1935) is an American composer associated with the minimalist school. ... In C is an aleatoric musical piece composed by Terry Riley in 1964 for any number of unspecified performers, but preferably 35 or more. ...

Non-ideal pulses varied according to strength or accents, which produce two or three pulse pulse groups (anything larger being a combination), strong-weak and strong-weak-weak (ibid). In fact, given an ideal pulse, the most probable reaction for one to have is to perceptually group or differentiate the beats. A pulse which became too fast would become a drone, a pulse that is too slow becomes isolated sounds. A pulse that is regularly accented is a meter. An isochronal or equally spaced pulse on one level that uses varied pulse groups (rather than just one pulse group the whole piece) create a pulse on the (slower) multiple level that is non-isochronal (a stream of 2+3... at the eighth note level would create a pulse of a quarter note+dotted quarter note as its multiple level). In music, an accent is an emphasis on a particular note created by length, as in an agogic accent, pitch, as in a pitch accent, and dynamics, such as dynamic accents. ... Metre or meter is the measurement of a musical line into measures of stressed and unstressed beats, indicated in Western notation by a symbol called a time signature. ... Metre is the measurement of a musical line into measures of stressed and unstressed beats, indicated in Western notation by a symbol called a time signature. ...

Pulse groups may further be distinguished as synchronous, if all pulses on slower levels coincide with those on faster levels, and nonsynchronous, if not. Synchronization is coordination with respect to time. ... Synchronization is coordination with respect to time. ...

See also

• beat (music).

See also the beat disambiguation page. ...

Source

• DeLone et. al. (Eds.) (1975). Aspects of Twentieth-Century Music. Englewood Cliffs, New Jersey: Prentice-Hall. ISBN 0-13-049346-5.