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Rhythm and polyrhythm
Rhythm and pitch are closer than they seem. A drum played four times a second is a rhythm. Speed it up to a hundred times a second and you hear a low note. In the same way, three beats against two, a polyrhythm, becomes a fifth when it is sped up, because the fifth is the ratio 3:2. Another link with mathematics is in how strokes are spread round a cycle: placing them as evenly as possible gives many of the bell patterns of West Africa and Cuba.