Composer is a top stylist (6)
I believe the answer is:
barber
This might be a double definition.
'composer' is the first definition.
(Samuel Barber)
'top stylist' is the second definition.
'barber' can be an answer for 'stylist' (barber is a kind of stylist). I'm not certain of the 'top' bit.
'is a' is the link.
Can you help me to learn more?
(Other definitions for barber that I've seen before include "Hairdresser who cuts and shaves" , "one to profit from the cuts?" , "Sweeney Todd's occupation in Fleet Street" , "producing various versions of Hair?" , "Man's hairdresser - from Seville?" .)