Graduates shortly collected instrument (7)
I believe the answer is:
bassoon
'instrument' is the definition.
(type of musical instrument)
'graduates shortly collected' is the wordplay.
'graduates' becomes 'BAs' (people with Bachelor of Arts degrees).
'shortly' becomes 'soon' (synonyms).
'collected' says to put letters next to each other.
'bas'+'soon'='BASSOON'
(Other definitions for bassoon that I've seen before include "So-so ban on the instruments" , "No, a boss would be a musical instrument" , "Instrument heard by Wedding-Guest" , "Double-reed instrument" , "So-so ban over the instrument" .)