It's played with subtle art in extremes of sound (5)
I believe the answer is:
strad
'it's played with subtle art in extremes of sound' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.
'it's played with subtle art in extremes of sound' is the wordplay.
'it' becomes ''t' (abbreviation. e.g. in 'tis).
'played with subtle art' becomes 'ra' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'in' is an insertion indicator.
'extremes of' means to remove the middle letters (only the letters at the extremes of the word).
'sound' with its middle taken out is 'sd'.
't'+'ra'='tra'
'tra' inserted inside 'sd' is 'STRAD'.
Can you help me to learn more?
(Other definitions for strad that I've seen before include "Top-quality violin (abbr.)" , "Valuable violin (abbrev.)" , "Noted violin" , "Famous violin" , "that Grappelli could have played" .)