Willing student joins a new orchestra (7)
I believe the answer is:
gamelan
'orchestra' is the definition.
(I've seen this before)
'willing student joins a new' is the wordplay.
'willing' becomes 'game' (game can mean willing to do something).
'student' becomes 'l' (as in L-plates for learner drivers).
'joins' is a charade indicator (letters next to each other).
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'game'+'l'+'a'+'n'='GAMELAN'
(Other definitions for gamelan that I've seen before include "exotic orchestra" , "Asian ensemble" , "instrument" , "Asian players" , "Balinese orchestra" .)