Perfect note on instrument, old before its time (7)
I believe the answer is:
utopian
'perfect' is the definition.
(associated in meaning)
'note on instrument old before its time' is the wordplay.
I cannot really understand how this works, but
'note' could be 'ut' (I've seen this in other clues) and 'ut' is located in the answer.
'old' could be 'o' (common abbreviation eg in OE for Old English) and 'o' is present in the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for utopian that I've seen before include "Ideal; imaginary" , "Perfect (state)" , "ideal but unrealistic" , "Of an ideal existence" , "Ideally perfect, but impracticable" .)