Search old jazz group (5)
I believe the answer is:
combo
'jazz group' is the definition.
(synonyms)
'search old' is the wordplay.
'search' becomes 'comb' (combing is a kind of searching).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'comb'+'o'='COMBO'
(Other definitions for combo that I've seen before include "Music group" , "Small pop group" , "Small jazz group" , "Small jazz or dance band" , "musicians" .)