Arrive shortly with puzzle for creative musician (8)
I believe the answer is:
composer
'for creative musician' is the definition.
(I've seen this before)
'arrive shortly with puzzle' is the wordplay.
'arrive' becomes 'come' (coming is a kind of arriving).
'shortly' means to remove the last letter.
'with' is a charade indicator (letters next to each other).
'puzzle' becomes 'poser' (poser can mean a mystery or puzzle).
'come' with its final letter removed is 'com'.
'com'+'poser'='COMPOSER'
(Other definitions for composer that I've seen before include "Creative musician" , "Bach, Beethoven or Mozart?" , "Bliss, perhaps" , "Eg, Arne, Bach, Chopin" , "Liszt or Ravel, say" .)