Lager brewed for a composer (5)
I believe the answer is:
elgar
'a composer' is the definition.
(Edward Elgar)
'lager brewed' is the wordplay.
'brewed' indicates anagramming the letters.
'lager' with letters rearranged gives 'ELGAR'.
'for' is the link.
(Other definitions for elgar that I've seen before include "The 18 [APOSTLES] creator" , "Glare strangely at the English composer" , "Enigma Variations composer" , "Nimrod composer" , "13 composer, 1857-1934" .)