beat time

Mark musical time by beating a drum, clapping, tapping the foot, or a similar means. For example, Even as a baby, Dave always beat time when he heard music. [Late 1600s]

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.