Little soft cry (4)
I believe the answer is:
weep
'cry' is the definition.
(I know that cry can be written as weep)
'little soft' is the wordplay.
'little' becomes 'wee' (similar in meaning).
'soft' becomes 'p' (musical abbreviation for 'piano').
'wee'+'p'='WEEP'
(Other definitions for weep that I've seen before include "Cry, shed tears" , "Seep slowly out" , "Sob - ooze" , "Greet" , "Pee-pee" .)