Currier partner (4)
I believe the answer is:
ives
'currier partner' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ives that I've seen before include "American composer of Three Places in New England, d. 1954" , "Charles -, American composer (The Unanswered Question)" , "Saint of Cornwall or Cambridgeshire" , "This classical composer" , "he composed" .)