Stick fiddle alongside old composer (7)
I believe the answer is:
rodrigo
'composer' is the definition.
(I've seen this before)
'stick fiddle alongside old' is the wordplay.
'stick' becomes 'rod' (I've seen this before).
'fiddle' becomes 'rig' (I've seen this before**).
'alongside' means one lot of letters go next to another.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'rod'+'rig'+'o'='RODRIGO'
(Other definitions for rodrigo that I've seen before include "Spanish scorer" , "Joaqoein -, Concierto de Aranjuez composer" , "Resident caretaker (in France)" , "Spanish composer (Concierto de Aranjuez)" .)