Cross-beat

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.African cross-rhythm is most prevalent within the greater Niger-Congo linguistic group, which dominates the continent south of the Sahara Desert.

[4] Jones observes that the shared rhythmic principles of Sub-Saharan African music traditions constitute one main system.

It is the interplay of the two elements that produces the cross-rhythmic texture.From the philosophical perspective of the African musician, cross-beats can symbolize the challenging moments or emotional stress we all encounter.

Playing cross-beats while fully grounded in the main beats, prepares one for maintaining a life-purpose while dealing with life’s challenges.

From the African viewpoint, the rhythms represent the very fabric of life itself; they are an embodiment of the people, symbolizing interdependence in human relationships.

The cross-rhythmic ratio three-over-two (3:2) or vertical hemiola, is the most significant rhythmic cell found in sub-Saharan rhythms.

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.

(b: "Main Beat Schemes")[6] The four-beat cycle is a shorter period than what is normally heard in European music.

The composite texture of the three-against-four cross rhythm produces a motif covering a length of the musical period.

The motif begins with the component beat schemes coinciding and continues with the beat schemes in alternate motions thus showing a progression from a "static" beginning to a "dynamic" continuationThe following pattern is an embellishment of the three-beat cycle, commonly heard in African music.

The 1.5:4 cross-rhythm is the basis for the open tone pattern of the enú (large batá drum head) for the Afro-Cuban rhythm changó (Shango).

Continuous duple-pulse cross-beats are often sounded by the quinto, the lead drum in the Cuban genres rumba and conga.

(Ladzekpo, b: "Main Beat Scheme")[6] Every triple-pulse pattern has its duple-pulse correlative; the two pulse structures are two sides of the same coin.

Some of their music examples are polymetric, with multiple and conflicting main beat cycles, each requiring its own separate time signature.

Polymeter fails to convey the true accentual structure of African music insofar as it creates the essential tension between a firm and stable background and a fluid foreground[The] term ‘polymetric’ is only applicable to a very special kind of phenomenon.

Being polymetric in the strict sense, these works can only be performed with several simultaneous conductorsWhen written within a single meter, we see that the dundun in the second line sounds the main beats, and the subdivision immediately preceding it.

(Clave Matrix p. 216)[7] Sub-Saharan instruments are constructed in a variety of ways to generate cross-rhythmic melodies.

These instruments are found in several forms indigenous to different regions of Africa and most often have equal tonal ranges for right and left hands.

The kalimba is a modern version of these instruments originated by the pioneer ethnomusicologist Hugh Tracey in the early 20th century which has over the years gained world-wide popularity.

Another instrument, the Marovany from Madagascar is a double sided box zither which also employs this divided tonal structure.

Also the fingers of each hand can play separate independent rhythmic patterns and these can easily cross over each other from treble to bass and back, either smoothly or with varying amounts of syncopation.

This characteristically African structure allows often simple playing techniques to combine with each other and produce cross-rhythmic music of great beauty and complexity.

"[24] The argument could be made that by nature of its simultaneous triple and duple subdivisions, swing is fundamentally a form of polyrhythm.

In 1959 Mongo Santamaria recorded "Afro Blue," the first jazz standard built upon a typical African 3:2 cross-rhythm.

The slashed noteheads are not bass notes, but are shown to indicate the main beats, where you would normally tap your foot to "keep time."

On the original "Afro Blue," drummer Willie Bobo played an abakuá bell pattern on a snare drum, using brushes.

Since the main beats (four sets of three pulses) are present whether sounded or not, this bell pattern can be considered an embellishment of the three-against-four (3:4) cross-rhythm.

[f] Jones inverted the metric hierarchy of Santamaria's composition, performing it instead as duple cross-beats over a 34 "jazz waltz" (2:3).

[g] The Wayne Shorter composition "Footprints" may have been the first overt expression of the 6:4 cross-rhythm (two cycles of 3:2) used by a straight ahead jazz group.