Proper to put notes next to coin (6)
I believe the answer is:
decent
'proper' is the definition.
(associated in meaning)
'notes next to coin' is the wordplay.
'notes' becomes 'de' (two musical notes).
'next to' is a charade indicator (letters next to each other).
'coin' becomes 'cent' (cent is a kind of coin).
'de'+'cent'='DECENT'
'to put' is the link.
(Other definitions for decent that I've seen before include "Proper; passable" , "Modest and respectable" , "Obliging or modest" , "Upright" , "Modest or kind" .)