Editing Rhythm (section)

===Pulse, beat and measure===

{{Further|Pulse (music)|Beat (music)}}
[[File:Metric levels.svg|thumb|right|upright=1.15|[[Metric level]]s: beat level shown in middle with division levels above and multiple levels below.]]

{{Blockquote|As a piece of music unfolds, its rhythmic structure is perceived not as a series of discrete independent units strung together in a mechanical, additive, way like beads [or "pulses"], but as an organic process in which smaller rhythmic motives, whole possessing a shape and structure of their own, also function as integral parts of a larger ["architectonic"] rhythmic organization.{{sfn|Cooper|Meyer|1960|p=2}}}}

Most music, dance and oral poetry establishes and maintains an underlying "metric level", a basic unit of time that may be audible or implied, the [[pulse (music)|pulse]] or ''tactus'' of the [[mensural level]],{{sfn|Berry|1987|p=349}}{{sfn|Lerdahl and Jackendoff|1983}}{{sfn|Fitch and Rosenfeld|2007|p=44}} or ''beat level'', sometimes simply called the [[beat (music)|beat]]. This consists of a (repeating) series of identical yet distinct [[Frequency|periodic]] short-duration [[stimulus (physiology)|stimuli]] perceived as points in time.{{sfn|Winold|1975|p=213}} The "beat" pulse is not necessarily the fastest or the slowest component of the rhythm but the one that is perceived as fundamental: it has a [[tempo]] to which listeners [[Entrainment (biomusicology)|entrain]] as they tap their foot or dance to a piece of music.{{sfn|Handel|1989}} It is currently most often designated as a crotchet or [[quarter note]] in western notation (see [[time signature]]). Faster levels are ''division levels'', and slower levels are ''multiple levels''.{{sfn|Winold|1975|p=213}} [[Maury Yeston]] clarified "Rhythms of recurrence" arise from the interaction of two levels of motion, the faster providing the pulse and the slower organizing the beats into repetitive groups.{{sfn|Yeston|1976|p=50–52}} "Once a metric hierarchy has been established, we, as listeners, will maintain that organization as long as minimal evidence is present".{{sfn|Lester|1986|p=77}}