Quiet vacation in Cornish town is escape (8)
I believe the answer is:
loophole
'is escape' is the definition.
(I've seen this before)
'quiet vacation in cornish town' is the wordplay.
'quiet' becomes 'p' (music symbol for 'piano', ie soft or quiet).
'vacation' becomes 'hol' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'in' indicates putting letters inside.
'cornish town' becomes 'looe' (I've seen this in other clues).
'p'+'hol'='phol'
'phol' placed inside 'looe' is 'LOOPHOLE'.
Can you help me to learn more?
(Other definitions for loophole that I've seen before include "Ambiguity that makes it possible to evade an obligation" , "Ambiguity in the law" , "Way of evading a rule or contract" , "A way to evade an obligation" , "unplanned escape" .)