Composer's eulogy airs occasionally (5)
I believe the answer is:
elgar
'composer's' is the definition.
(I've seen this before)
'eulogy airs occasionally' is the wordplay.
'occasionally' means one should take alternating letters.
'eulogy'+'airs'='eulogyairs'
The alternate letters of 'eulogyairs' are 'ELGAR'.
(Other definitions for elgar that I've seen before include "13 composer, 1857-1934" , "Scorer" , "Score-person" , "Enigma Vars. composer" , "Enigma Variations composer" .)