keep time

1. Maintain the correct tempo and rhythm of music; also, mark the rhythm by foot-tapping, hand movements, or the like. For example, The children love to keep time by clapping their hands . This usage dates from the late 1500s and is occasionally put figuratively, as Ben Jonson did in Cynthia's Revels (1699): “Slow, slow, fresh fount, keep time with my salt tears.”

2. Also, keep good time . Indicate the correct time, as in This inexpensive watch does not keep good time . [Late 1800s]