Cheer snob somehow beginning to get composer (10)
I believe the answer is:
schoenberg
'composer' is the definition.
(I've seen this before)
'cheer snob somehow beginning to get' is the wordplay.
'somehow' indicates an anagram.
'beginning to' indicates taking the first letters.
The first letter of 'get' is 'g'.
'cheer'+'snob'='cheersnob'
'cheersnob' with letters rearranged gives 'schoenber'.
'schoenber'+'g'='SCHOENBERG'
(Other definitions for schoenberg that I've seen before include "Austrian scorer" , "Arnold --, Austrian-born composer" .)