Editing Rhythm (section)

==Anthropology==
[[File:Traditional indonesian instruments02.jpg|thumb|upright=1.35|Percussion instruments have clearly defined sounds that aid the creation and perception of complex rhythms.]]

In his television series ''How Music Works'', [[Howard Goodall]] presents theories that human rhythm recalls the regularity with which we walk and the heartbeat.{{sfn|Goodall|2006|loc=0:03:10}} Other research suggests that it does not relate to the heartbeat directly, but rather the speed of emotional affect, which also influences heartbeat. Yet other researchers suggest that since certain features of human music are widespread, it is "reasonable to suspect that beat-based rhythmic processing has ancient evolutionary roots".{{sfn|Patel|2014|p=1}} Justin London writes that musical metre "involves our initial [[perception]] as well as subsequent anticipation of a series of beats that we abstract from the rhythm surface of the music as it unfolds in time".{{sfn|London|2004|p=4}} The "perception" and "abstraction" of rhythmic measure is the foundation of human instinctive musical participation, as when we divide a series of identical clock-ticks into "tick-tock-tick-tock".{{sfn|Scholes|1977b}}{{sfn|Scholes|1977c}}

{{Image frame|content=<score raw="1" sound="1">
\version "2.22.0"
\header { tagline = ##f}
\score {
  \drums \with {midiInstrument = "drums"}
  \with { \numericTimeSignature }
  {
    \repeat volta 2 {
      <<
        \tempo 4 = 80-160
        \bar ".|:"
        {
          cymra8 [cymra] cymra [cymra]  cymra [cymra] cymra [cymra]
        }\\{bd4 sne bd sne}
      >>\break
    }
  }
  \layout {}
}
\score {
  \unfoldRepeats {
    \drums \with {midiInstrument = "drums"}{
      \repeat volta 2 {

        <<
          \tempo 4 = 80-160
          \bar ".|:"
          {
            cymra8 [cymra] cymra [cymra]  cymra [cymra] cymra [cymra]
          }\\{bd4 sne bd sne}
        >>\break
      }
    }
  }
  \midi { \tempo  4 = 90 }
}
</score>|width=300|align=right|caption=A simple [quadr][[duple meter|duple]] [[drum pattern]], which lays a foundation of duration common in popular music|max-width=300}}

[[Joseph Jordania]] recently suggested that the sense of rhythm was developed in the early stages of [[hominid]] evolution by the forces of [[natural selection]].{{sfn|Jordania|2011|pp=99–101}} Plenty of animals walk rhythmically and hear the sounds of the heartbeat in the womb, but only humans have the ability to be engaged ([[Entrainment (biomusicology)|entrained]]) in rhythmically coordinated vocalizations and other activities. According to Jordania, development of the sense of rhythm was central for the achievement of the specific neurological state of the battle trance, crucial for the development of the effective defense system of early hominids. Rhythmic [[Battle cry|war cry]], rhythmic drumming by [[shaman]]s, rhythmic [[drilling]] of the soldiers and contemporary professional combat forces listening to the heavy rhythmic rock music{{sfn|Pieslak|2009|p={{Page needed|date=April 2016}}}} all use the ability of rhythm to unite human individuals into a shared [[collective identity]] where group members put the interests of the group above their individual interests and safety.

Some types of parrots can know rhythm.{{sfn|Anon.|2009}} Neurologist [[Oliver Sacks]] states that [[chimpanzee]]s and other animals show no similar appreciation of rhythm yet posits that human affinity for rhythm is fundamental, so that a person's sense of rhythm cannot be lost (e.g. by stroke). "There is not a single report of an animal being trained to tap, peck, or move in synchrony with an auditory beat",<ref>{{harvnb|Patel|2006}}, cited in {{harvnb|Sacks|2007|pp=239–240}}</ref> Sacks write, "No doubt many pet lovers will dispute this notion, and indeed many animals, from the [[Lipizzan]]er horses of the [[Spanish Riding School]] of Vienna to performing circus animals appear to 'dance' to music. It is not clear whether they are doing so or are responding to subtle visual or tactile cues from the humans around them."{{sfn|Sacks|2007|pp=239–240}} Human rhythmic arts are possibly to some extent rooted in courtship ritual.{{sfn|Mithen|2005|p={{Page needed|date=July 2014}}}}

[[File:Compound triple drum pattern.png|thumb|Compound triple drum pattern: divides three beats into three; contains repetition on three levels [[File:Compound triple drum pattern.mid|thumb|left]]]]

The establishment of a basic beat requires the perception of a regular sequence of distinct short-duration pulses and, as a subjective perception of loudness is relative to background noise levels, a pulse must decay to silence before the next occurs if it is to be really distinct. For this reason, the fast-transient sounds of percussion instruments lend themselves to the definition of rhythm. Musical cultures that rely upon such instruments may develop multi-layered [[polyrhythm]] and simultaneous rhythms in more than one time signature, called [[polymeter]]. Such are the [[Rhythm in Sub-Saharan Africa#Cross-rhythm|cross-rhythms of Sub-Saharan Africa]] and the [[Kotekan|interlocking ''kotekan'']] rhythms of the [[gamelan]].

For information on rhythm in [[Music of India|Indian music]] see [[Tala (music)]]. For other Asian approaches to rhythm see [[Rhythm in Persian music]], [[Rhythm in Arabic music]] and [[Usul (music)|''Usul''—Rhythm in Turkish music]] and [[Dumbek rhythms]].