Noble old general giving up whiskey for jazzman (4,9)
I believe the answer is:
duke ellington
'jazzman' is the definition.
(jazz pianist)
'noble old general giving up whiskey' is the wordplay.
'noble' becomes 'duke' (duke is a kind of noble).
'old general' becomes 'Wellington' (Duke of Wellington).
'giving up' is a deletion indicator.
'whiskey' becomes 'W' (alpha bravo charlie delta ...).
'wellington' with 'w' taken out is 'ellington'.
'duke'+'ellington'='DUKE ELLINGTON'
'for' is the link.
(Other definitions for duke ellington that I've seen before include "US band leader" , "Mood Indigo composer, d. 1974" , "Key player" , "US jazz bandleader" , "Jazzman" .)