Wild money-changing securing bric-a-brac (7)
I believe the answer is:
agitato
'wild' is the definition.
(I've seen this before)
'money-changing securing bric-a-brac' is the wordplay.
'money changing' becomes 'agio' (I've seen this in another clue).
'securing' indicates putting letters inside.
'bric-a-brac' becomes 'tat' (I've seen this before).
'agio' enclosing 'tat' is 'AGITATO'.
(Other definitions for agitato that I've seen before include "Excited" , "Excitedly (music)" , "Disturbed playing" , "Troubled, nervous (music)" , "Restless, wild (musical term)" .)