chin music

Meanings

1. A fastball thrown near the batter's chin, often to set up a subsequent pitch thrown low and outside.
2. A bouncer aimed near the batsman's chin.
3. Idle talk; chatter.
4. Rhythmic singing, usually to nonsense syllables, in a style partly inspired by the instruments used to accompany folk dancing in Irish and Scottish traditions.

Etymology

(folk music): The name jokingly refers to "playing" the mouth as if it were an instrument.