Odd job with an instrument (5)
I believe the answer is:
banjo
'instrument' is the definition.
(banjo is a kind of instrument)
'odd job with an' is the wordplay.
'odd' is an anagram indicator.
'with' indicates putting letters inside.
'job' is an anagram of 'bjo'.
'bjo' placed around 'an' is 'BANJO'.
(Other definitions for banjo that I've seen before include "Relative of the guitar" , "String instrument" , "Stringed instrument like guitar with round body" , "strumming instrument" , "Softly (music)" .)