Band in performance that's barely finished (5)
I believe the answer is:
strip
This clue is a double definition.
'band' is the first definition.
(both can mean a small piece of material)
'performance that's barely finished' is the second definition.
(as in a strip tease - the performer ends up bare)
'in' is the link.
(Other definitions for strip that I've seen before include "Ribbon" , "Undress (provocatively)" , "Undress - maybe comic!" , "Tear off" , "Kind of lighting" .)