Rhythm comes from the Greek word rhythmos, meaning "regular, repeating motion or symmetry." It refers to a pattern of movement or sound that repeats in a regular way, such as the mix of strong and weak beats or changes between different conditions. This idea of regular repetition can be found in many natural events, from very quick patterns lasting microseconds to longer ones that take seconds, minutes, hours, or even years.
The Oxford English Dictionary explains that rhythm is the way words and phrases flow in poetry, creating patterns based on the length and stress of syllables in a line of verse.
Rhythm is connected to but different from pulse, meter, and beats. In performing arts, rhythm describes the timing of events, such as the timing of musical notes and silences, dance steps, or the rhythm in spoken language and poetry. In styles like hip hop music, the rhythm of lyrics is a key part of the style. Rhythm can also describe visual patterns, such as the way movement appears over time in art or the spacing of windows and columns in a building’s design. These patterns create a sense of order and movement.
Experts in music study rhythm and meter. Books by authors like Maury Yeston, Fred Lerdahl, and others explore these topics in detail.
Anthropology
Joseph Jordania recently proposed that the ability to sense rhythm developed early in human evolution due to natural selection. Many animals move rhythmically and can hear heartbeats in the womb, but only humans can synchronize their voices and actions with rhythm. Jordania believes that developing a sense of rhythm was important for creating a focused mental state called battle trance, which helped early humans defend themselves. Examples of this include rhythmic war cries, drumming by shamans, soldiers drilling in rhythm, and modern soldiers listening to heavy rock music. These activities help people work together as a group, putting the group’s needs above their own.
Some parrots can recognize rhythm. Neurologist Oliver Sacks explains that chimpanzees and other animals do not seem to understand rhythm the way humans do. He says humans have a strong natural ability to sense rhythm, which is so important that it cannot be lost, even if someone has a brain injury. Sacks notes that no animals have been trained to move in time with music, even though some animals, like trained horses or circus animals, appear to dance to music. It is unclear if they are truly responding to rhythm or reacting to visual or physical signals from people nearby. Human rhythmic arts may have started with behaviors related to finding a partner.
Creating a basic rhythm requires hearing a pattern of short, clear sounds. Because loudness depends on background noise, each sound must stop completely before the next one begins to be clearly heard. For this reason, the quick, sharp sounds of percussion instruments are well-suited for making rhythm. Musical traditions that use these instruments often create complex rhythms, such as layered patterns called polyrhythm or rhythms that follow different time patterns at the same time, called polymeter. These techniques are seen in cross-rhythms from Sub-Saharan Africa and interlocking rhythms in Indonesian gamelan music.
For more information about rhythm in Indian music, see Tala (music). For other Asian musical traditions, see Rhythm in Persian music, Rhythm in Arabic music, Usul—Rhythm in Turkish music, and Dumbek rhythms.
Terminology
Most music, dance, and oral poetry use a basic timing unit called the "metric level." This unit is the beat or pulse, which is the repeating pattern of short time intervals that listeners can feel or hear. The beat is not always the fastest or slowest part of the rhythm, but it is the one that feels most important. People often tap their feet or move to this beat. In Western music, the beat is usually shown as a quarter note in musical notation. Faster parts of the rhythm are called "division levels," and slower parts are called "multiple levels." Maury Yeston explained that rhythms repeat because of two levels of movement: the faster one creates the beat, and the slower one groups beats into patterns. Once a rhythm is established, listeners keep following it as long as there is enough evidence to recognize it.
A time pattern that matches the beat is called a "rhythmic unit." These can be grouped into four types:
– Metric: Even patterns, like steady eighth notes.
– Intrametric: Patterns that confirm the beat, such as dotted eighth-sixteenth notes or swing rhythms.
– Contrametric: Patterns that do not follow the beat, like syncopated rhythms.
– Extrametric: Irregular patterns, like triplets.
A "rhythmic gesture" is any time pattern that does not match the beat exactly. It can be described by when it starts or ends or by the rhythmic units it contains. If a rhythm starts on a strong beat, it is called thetic. If it starts on a weak beat, it is anacrustic. If it starts after a rest or tied note, it is initial rest. If it ends on a strong beat, it is strong. If it ends on a weak beat, it is weak. If it ends on an upbeat (a weak beat before the strong beat), it is upbeat.
Rhythm is created by the repeated pattern of strong and weak beats, played notes, and silent rests. Humans can also predict rhythm if the pattern is short enough to remember. The alternation between strong and weak beats is important in poetry, dance, and music. In poetry, the term "foot" refers to the pattern of lifting and tapping a foot in time. In music, terms like "upbeat" and "downbeat" describe the timing of beats. These patterns help create a two-level rhythm structure. A group of beats with accents and rests forms a "pulse-group," which matches the poetic foot. Usually, a pulse-group starts with the most accented beat and continues until the next accent. A rhythm that shifts the emphasis from the expected beat is called syncopated rhythm.
Most complex rhythms can be broken into simple patterns of two or three beats, either by adding or dividing beats. According to Pierre Boulez, in Western music, rhythms with more than four beats are not common.
The tempo of a piece is the speed of the beat, measured in "beats per minute" (BPM). For example, 60 BPM means one beat every second. A rhythmic unit is a time pattern that matches the beat or several beats. The longer a rhythmic unit is, the slower the tempo.
Musical sound can be analyzed on five time scales, as described by Moravscik:
– Supershort: A single wave cycle, too fast to be heard as separate events.
– Short: About one second, matching the range of typical musical tempo (40–240 BPM).
– Medium: A few seconds, allowing the definition of rhythmic units and musical phrases.
– Long: Many seconds or minutes, matching the length of musical sections or dance moves.
– Very long: Minutes or hours, matching the structure of entire compositions.
Curtis Roads expanded this to nine time scales, including extremely short and long durations. His "macro level" matches Moravscik's "very long" scale, and his "meso level" matches "long." His "sound object" and "microsound" correspond to "short" and "supershort" scales.
One challenge in understanding rhythm is that how we hear it depends on tempo, and how we hear tempo depends on rhythm. This relationship is influenced by context. For example, in Modest Mussorgsky's Promenade from Pictures at an Exhibition, the rhythm is heard as it is, not as a faster repetition of the same pattern. This is explained by the principle of correlative perception, where the brain finds the simplest way to understand patterns. According to Kolmogorov's complexity theory, this means the brain looks for the pattern that uses the least memory.
Composite rhythm
A composite rhythm is the way the lengths and patterns of notes are created when all the parts in a musical piece are played together. In music from the common practice period, this rhythm usually matches the meter, often following regular patterns that align with the beat on a specific level. White described composite rhythm as "how the rhythm is arranged across all the different musical parts in a piece." At the same time, Maury Yeston called it "attack point rhythm" in 1976, defining it as "the most noticeable rhythmic part of a composition—the surface layer where movement is clearly heard."
Counter rhythm
From 1927 onward, the accepted definition of "Counter Rhythm" is "A supporting rhythm that balances the main rhythm" (OED). The term "Counter Rhythm" is not commonly used in the English language, appearing about 0.01 times in every million words in modern written English. Its usage has steadily declined since it was first recognized, except for a brief increase in the 1970s. Earlier definitions that are no longer used include, "The musical counter-rhythms which Marlowe introduced" and "Splashes of counter-rhythms, flashing tremolos" (OED).
In different traditions
In the Griot tradition of Africa, music has been shared through spoken words instead of written symbols. Babatunde Olatunji (1927–2003) created a simple system of spoken sounds to teach the rhythms of a hand-drum. He used six sounds—"Goon, Doon, Go, Do, Pa, Ta"—to represent three basic drum beats, each played with the left or right hand. Some people debate whether written musical symbols, called staff notation, are suitable for African music. However, many African scholars have accepted the use of staff notation and created written versions of music to help others learn and discuss it.
John Miller explained that West African music often uses complex rhythms, where two or more different rhythms are played at the same time. One rhythm is usually stronger, while others may compete or support it. These rhythms are built on repeated simple patterns that meet at specific points, and they often follow a call-and-response style. Shared sayings, like proverbs or family histories, are sometimes translated into drum sounds or included in songs. Musicians are expected to encourage audience participation by responding to dancers. People value musicians who help maintain traditions and community values through their music.
In Indian music, rhythms have also been taught through spoken words. Tabla players first learn to speak rhythm patterns before playing them on instruments. Sheila Chandra, a singer of Indian heritage, performed songs based on these spoken rhythms. In Indian classical music, a Tala is a specific rhythmic pattern that structures a musical piece.
During the 20th century, composers like Igor Stravinsky, Béla Bartók, Philip Glass, and Steve Reich created music with complex rhythms using unusual time signatures and techniques like phasing and adding rhythms step by step. At the same time, composers such as Olivier Messiaen and his students used complicated rhythms to avoid a regular beat, leading to the use of irregular rhythms in a style called New Complexity. John Cage suggested that regular rhythms make sounds seem like a group, while irregular rhythms help listeners notice changes in pitch. La Monte Young composed music without a regular beat, using long, continuous tones. In the 1930s, Henry Cowell wrote music with multiple overlapping rhythms and worked with Leon Theremin to create the rhythmicon, the first electronic rhythm machine. Conlon Nancarrow also wrote music for player pianos to perform complex rhythms.
Linguistics
In linguistics, rhythm or equal timing is one of the three parts of prosody, along with stress and intonation. Languages can be grouped based on whether they are syllable-timed, mora-timed, or stress-timed. In syllable-timed languages like Spanish and Cantonese, each syllable is spoken for about the same amount of time. In contrast, in stress-timed languages like English and Mandarin Chinese, the time between stressed syllables is roughly equal, and the timing of unstressed syllables in between is adjusted to fit this pattern.
Narmour describes three types of prosodic rules that create rhythmic patterns: additive (repeating the same duration), cumulative (short followed by long), or countercumulative (long followed by short). Cumulative rhythms are linked to feelings of closure or relaxation, while countercumulative rhythms are connected to openness or tension. Additive rhythms are open-ended and repetitive. Richard Middleton notes that this method does not explain syncopation, which involves shifting rhythm patterns, and suggests the idea of transformation to address this.