Belly dance grew out of the rhythmic influences of traditional Eastern music. This music is fundamentally different from music in the West. Western music depends upon a regular rhythm and melodies which build upon a progression of chords and relies on changes in tempo for variety. There is a near absence of standard tempos of music. Vocal music is allowed complete freedom from standard tempo or rhythm when not accompanied by a rhythm instrument.
Eastern rhythms are additive, whereas western rhythms are multiplicative.
This means that western rhythms break down evenly. The rhythms can be highly complex, with patterns sometimes consisting of as many as 48 beats. In the late nineteenth century the kamanjah was replaced with the Western violin, that remained as a folk instrument under the name rababah. After World War I, the takht was gradually expanded into an orchestra that combined these Arab instruments and other instruments borrowed from the West, especially instruments of the violin family. An instrument frequently used by belly dancers to accompany their dance is finger cymbals.