Bloke playing old fashionable instrument (8)
I believe the answer is:
mandolin
'instrument' is the definition.
(mandolin is a kind of instrument)
'bloke playing old fashionable' is the wordplay.
'bloke' becomes 'man' (I've seen this in other clues).
'playing' indicates anagramming the letters.
'fashionable' becomes 'in' ('in' can be similar in meaning to 'fashionable').
'old' is an anagram of 'dol'.
'man'+'dol'+'in'='MANDOLIN'
(Other definitions for mandolin that I've seen before include "Small guitar-like instrument" , "Musical instrument like a small lute" , "vegetable slicer" , "Musical instrument like a small guitar" , "Almond in the stringed instrument, oddly" .)