Large combo (5)
I believe the answer is:
octet
'large combo' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for octet that I've seen before include "What takes members up to eighth" , "Mendelssohn or Schubert piece" , "A number of musicians" , "Work for eight players" , "Group of eight players" .)