Disentangle one French composer (7)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
unravel
'disentangle' is the definition.
(I know that unravel is a more specific form of the action disentangle)
'one french composer' is the wordplay.
'one' becomes 'un' (northern English dialect form of 'one').
'french composer' becomes 'Ravel' (Maurice Ravel).
'un'+'ravel'='UNRAVEL'
(Other definitions for unravel that I've seen before include "Make sense of" , "Disentangle knitted wool or solve mystery" , "Straighten out" , "Unpick, untangle" , "Solve the problem" .)