One of Elgar's variations incorporated into finale and added to (8)
I believe the answer is:
enlarged
'added to' is the definition.
The answer and definition can be both related to change as well as being past participle verbs.
Perhaps there's an association between them I don't understand?
'one of elgar's variations incorporated into finale and' is the wordplay.
'one of' is an anagram indicator (the answer comes from or 'of' the letters).
'variations' becomes 'en' (I am not sure about this - if you are sure you should believe this answer much more).
'incorporated into' is an insertion indicator.
'finale' indicates one should take the final letters.
The last letter of 'and' is 'd'.
'elgar' is an anagram of 'large'.
'large' enclosing 'en' is 'enlarge'.
'enlarge'+'d'='ENLARGED'
Can you help me to learn more?
(Other definitions for enlarged that I've seen before include "Elaborated or made bigger" , "Made greater" , "Expanded, amplified" , "Bloated" , "Blew up" .)