In music and music theory, the beatis the basic unit of time, the pulse of the mensural level (or beat level). In popular use, the beat can refer to a variety of related concepts including: tempo, meter, rhythm andgroove. In modern pop music, the term "beats" has been used to describe whole pieces of composed music. This is a distinct and separate use of the term from the way "beat" is used traditionally as related only to the rhythmic element of music.
Rhythm in music is characterized by a repeating sequence of stressed and unstressed beats (often called "strong" and "weak") and divided into bars organized by time signature and tempoindications.
The downbeat is the impulse that occurs at the beginning of a bar in measured music. Its name is derived from the downward stroke of the director or conductor's baton on the first beat of each measure. It frequently carries the strongest accent of the rhythmic cycle. However, in some cases, the downbeat may not be emphasized. Such departure from the normal stress pattern of a measure is a form of syncopation.
1. An unaccented beat or beats that occur before the first beat of the followingmeasure. In other words, this is an impulse in a measured rhythm that immediately precedes, and hence anticipates, the downbeat. It can be the last beat in a bar where that bar precedes a new bar of music.
2. An anticipatory note or succession of notes occurring before the first barline of a piece, sometimes referred to as an ‘upbeat figure’, section or phrase. An alternative expression is "anacrusis" (from Greek. ana: "up towards" and krousis: "to strike"; Fr. anacrouse). This term was borrowed from poetry where it refers to one or more unstressed extrametrical syllables at the beginning of a line.
3. The upward stroke made by a conductor to indicate the beat that leads into a new measure.
On-beat and off-beat
In music that progresses regularly in 4/4 time, counted as "1 2 3 4, 1 2 3 4...", the first beat of the bar (down-beat) is usually the strongest accent in the melody and the likeliest place for a chord change, the third is the next strongest: these are "on" beats. The second and fourth are weaker - the "off-beats". Subdivisions (like eighth notes) that fall between the pulse beats are even weaker and these, if used frequently in a rhythm, can also make it "off-beat". The effect can be easily simulated by evenly and repeatedly counting to four: Bold denotes a stressed beat. As a background against which to compare these various rhythms a bass drum strike on the downbeat and a constant eighth note subdivision on ride cymbal have been added, which would be counted as follows:
So Off-beat is a musical term commonly applied to syncopation that emphasizes the weak even beats of a bar, as opposed to the "normal" on-beat. This is a fundamental technique of African polyrhythm that transferred to popular western music. According to Grove Music, the “Offbeat” is [often] where the downbeat is replaced by a rest or is tied over from the preceding bar". The downbeat can never be the off-beat because it is the strongest beat in 4/4 time. Certain genres in particular tend to emphasize the off-beat. This emphasis is a defining characteristic of rock'n'roll and Ska music.
Tamlyn found slap bass executions on the backbeat in styles of country western music of the 1930s, and the late 40s early 50s music a Hank Williams reflected a return to strong backbeat accentuation as part of the honky tonk style of country. In the mid 1940s "hillbilly" musicians theDelmore Brothers were turning out boogie tunes with a hard driving back beat, such as the #2 hit "Freight Train Boogie" in 1946, as well as in other boogie songs they recorded. Similarly Fred Maddox’s trademark back beat, a slapping bassstyle, helped drive a rhythm that came to be known as rockabilly, one of the early forms of rock and roll. Maddox had used this style as early as 1937.
In today's popular music the snare drum is typically used to play the backbeat pattern. Early funk music often delayed one of the backbeats so as, "to give a 'kick' to the [overall] beat".
Cross-rhythm. A rhythm in which the regular pattern of accents of the prevailing meter is contradicted by a conflicting pattern and not merely a momentary displacement that leaves the prevailing meter fundamentally unchallenged—New Harvard Dictionary of Music (1986: 216).
The cross-rhythmic ratio three-over-two (3:2) or vertical hemiola, is the most significant rhythmic cell found in sub-Saharan rhythms. The following measure is evenly divided by three beats and two beats. The two cycles do not share equal status though. The two bottom notes are the primary beats, the ground, the main temporal referent. The three notes above are the secondary beats. Typically, the dancer's feet mark the primary beats, while the secondary beats are accented.
The example below shows the African 3:2 cross-rhythm within its proper metric structure.
Novotney observes: "The 3:2 relationship (and [its] permutations) is the foundation of most typical polyrhythmic textures found in West African musics." 3:2 is the generative or theoretic form of sub-Saharan rhythmic principles. Agawu succinctly states: "[The] resultant [3:2] rhythm holds the key to understanding . . . there is no independence here, because 2 and 3 belong to a single Gestalt."
The three-against-four (3:4) cross-rhythm consists of a "slow" cycle of three beats over four main beats. The three-beat cycle is represented as half-notes in the following example for visual emphasis.
A hyperbeat is one unit of hypermeter, generally a measure. "Hypermeter is meter, with all its inherent characteristics, at the level where measures act as beats."
Afterbeat refers to a percussion style where a strong accent is sounded on the second, third and fourth beats of the bar, following the downbeat.
In Reggae music, the term One Dropreflects the complete de-emphasis (to the point of silence) of the first beat in the cycle.
James Brown’s signature funk groove emphasized the downbeat – that is, with heavy emphasis "on the one" (the first beat of every measure) – to etch his distinctive sound, rather than the back beat (familiar to many R&B musicians) which places the emphasis on the second beat.