Related Clues:
- Like Pentatonix performances
- Lacking backing, in a way
- Barbershop quartet style
- With no instrumental accompaniment
- Like singing sans instruments
- Nearly all clap ape surprisingly singing like this?
- Like some college singing groups
- Like Pentatonix numbers
- How Gregorian chant is sung
- Unaccompanied singing in palace -- with lap dancing!
- Singing without instrumental accompaniment
- Without instrumental backup
- Like singing in the rain, usually
- A better rice dish American put away, wanting accompaniment
- Unaccompanied, in a way