BEAT – Footfall of a hoof or a diagonal pair of hooves that strike the ground virtually simultaneously. The timing of the footfalls determines the rhythm of the stride. The walk has four beats per stride (only two of which are emphasized beats perceived by the rider), the trot has two beats per stride, and the canter has three beats per stride (only one of which is the emphasized beat perceived by the rider).
See also Beat in Freestyle Music section, and Tempo (regarding counting beats to determine tempo).
Full glossary: http://bit.ly/2019USDFGlossary
