Fan must start in line to see player (15)
I believe the answer is:
instrumentalist
'player' is the definition.
(someone who plays an instrument)
'fan must start in line' is the wordplay.
'fan' indicates anagramming the letters (letters must be fanned around).
'must'+'start'+'in'+'line'='muststartinline'
'muststartinline' with letters rearranged gives 'INSTRUMENTALIST'.
'to see' acts as a link.
(Other definitions for instrumentalist that I've seen before include "one of the band" , "musician" , "oboe, perhaps" .)