Student in a crowd to see the composer (5)
I believe the answer is:
holst
'the composer' is the definition.
(Gustav Holst)
'student in a crowd' is the wordplay.
'student' becomes 'l' (as in L-plates for learner drivers).
'in' indicates putting letters inside.
'a crowd' becomes 'host' (both can mean a large number of people).
'l' placed within 'host' is 'HOLST'.
'to see' is the link.
(Other definitions for holst that I've seen before include "Planets Suite composer" , "musical writer" , "British composer, 1874-1934" , "Composer of The Planets, d. 1934" , "Gustav --, English composer" .)