One of the composers, ie, in Bruch, Brahms and Liszt (9)
I believe the answer is:
cherubini
'one of the composers' is the definition.
(Italian composer Luigi Cherubini)
'ie in bruch brahms and liszt' is the wordplay.
'brahms and liszt' is an anagram indicator (Cockney rhyming slang for 'pissed', i.e. drunk).
'ie'+'in'+'bruch'='ieinbruch'
'ieinbruch' with letters rearranged gives 'CHERUBINI'.
(Other definitions for cherubini that I've seen before include "composer" , "author of church music" .)