Related Clues:
- Signals in charades
- Signaled yeses
- Acknowledges silently
- Commends a very quiet hour of prayer
- They can mean 'yes'
- Signs agreement without senior detective
- Non-verbal indications of assent
- Approving bobs
- Subtle auction bids
- Gives applause
- Moves of agreement
- What music brings to faces
- Audition acceptances
- Headbanger does this during slow jams, perhaps
- Good band hears them from crowd