The human brain appears biased toward hearing and producing rhythms with simple integer ratios, but the favored ratios can vary greatly between different societies, according to a 15-country study.

Music is intimately associated with experiences of emotions. Rhythmic entrainment is a possible mechanism of emotion that can be evoked by music. Rhythmic entrainment also binds individuals together ...

But in certain situations -- outracing or outmaneuvering a predator, for example -- the ratios of those periods change drastically. In the design of robots built to emulate dogs, fish or birds, ...