Piece is quiet, owing to time (5,4)
I believe the answer is:
piano duet
'piece' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.
'quiet owing to time' is the wordplay.
I cannot quite understand how this works, but
'quiet' could be 'piano' (I've seen this before) and 'piano' is found in the answer.
'owing' could be 'due' (similar in meaning) and 'due' is found within the answer.
'time' could be 't' (abbreviation) and 't' is found within the answer.
No letters remain.
This explanation may well be incorrect...
'is' is the link.
Can you help me to learn more?
(Another definition for piano duet that I've seen is " Keyboard composition".)