Group of musicians from Oregon clubs, breaking hearts (9)
I believe the answer is:
orchestra
'group of musicians' is the definition.
(I've seen this before)
'oregon clubs breaking hearts' is the wordplay.
'oregon' becomes 'or'.
'clubs' becomes 'c' (abbreviation used in card games such as bridge).
'breaking' indicates an anagram.
'hearts' anagrammed gives 'hestra'.
'or'+'c'+'hestra'='ORCHESTRA'
'from' acts as a link.
(Other definitions for orchestra that I've seen before include "Musicians, maybe in theatre" , "Eg, LSO, RPO" , "Group of musical instrumentalists" , "A number of musicians" , "many players" .)