Lord with a bit of wisdom, not quiet? (4)
I believe the answer is:
earl
'lord' is the definition.
(earl is a kind of lord)
'bit of wisdom not quiet?' is the wordplay.
'bit of wisdom' becomes 'pearl' (I've seen this in another clue).
'not' indicates named letters should be taken away.
'quiet?' becomes 'p' (music symbol for 'piano', ie soft or quiet).
'pearl' with 'p' taken out is 'EARL'.
'with a' is the link.
(Other definitions for earl that I've seen before include "Male member of British nobility" , "British nobleman" , "Peer of the realm" , "Jimmy Carter's middle name" , "Sandwich perhaps" .)