US chap - he will appear in unsatisfactory opera (2,6)
I believe the answer is:
la boheme
'opera' is the definition.
(I've seen this before)
'us chap he will appear in unsatisfactory' is the wordplay.
I cannot quite see how this works, but
'us' could be 'me' ('us' can mean 'mean' in some UK dialects) and 'me' is found in the answer.
'chap' could be 'bo' and 'bo' is found in the answer.
'he' is found in the answer.
The remaining letters 'la' is a valid word which might be clued in a way I don't see.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for la boheme that I've seen before include "18 [OPERA]" , "musical work" , "Opera by Puccini" .)