Graduate, with collection of books on artist, repeated phrase (6)
I believe the answer is:
mantra
'repeated phrase' is the definition.
(I've seen this before)
'graduate with collection of books on artist' is the wordplay.
'graduate' becomes 'ma' (abbreviation for Master of Arts).
'with' means one lot of letters go next to another.
'collection of books' becomes 'nt' (New Testament).
'on' means one lot of letters go next to another.
'artist' becomes 'ra' (Royal Academician, member of Royal Academy of Arts).
'ma'+'nt'+'ra'='MANTRA'
(Other definitions for mantra that I've seen before include "Incantation used as aid to meditation" , "Commonly repeated word or phrase, with religious connotation perhaps" , "Word aiding meditation (Buddhism)" , "Repetitive sacred utterance" , "Word repeated as aid to concentration during meditation" .)