Talk madly, having left composer (5)
I believe the answer is:
ravel
'composer' is the definition.
(Maurice Ravel)
'talk madly having left' is the wordplay.
'talk madly' becomes 'rave' (I've seen this in another clue).
'having' is a charade indicator (letters next to each other).
'left' becomes 'l' (common abbreviation).
'rave'+'l'='RAVEL'
(Other definitions for ravel that I've seen before include "French composer, Maurice (1875-1937)" , "Tangle - untangle - French composer, d. 1937" , "Bolero's composer" , "Entangle - French composer, d. 1937" , "Tangle or become tangled" .)