Plaintive note on current account (7)
I believe the answer is:
elegiac
'plaintive' is the definition.
(I've seen this before)
'note on current account' is the wordplay.
'note' becomes 'e' (musical note).
'on' becomes 'leg' (cricket term).
'current' becomes 'I' (symbol for electric current).
'account' becomes 'ac' (abbreviation for account).
'e'+'leg'+'i'+'ac'='ELEGIAC'
(Other definitions for elegiac that I've seen before include "Wistful, mournful" , "Mournful like a sorrowful poem" , "Mournful, lamenting" , "Like classical couplets" , "Plaintive" .)