Business backing song about new music-maker (7)
I believe the answer is:
ocarina
'music-maker' is the definition.
(type of musical instrument)
'business backing song about new' is the wordplay.
'business' becomes 'co' (short for company).
'backing' shows that the letters should be reversed in order.
'song' becomes 'aria' (aria is a kind of song).
'about' means one lot of letters goes inside another.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'co' in reverse letter order is 'oc'.
'aria' going around 'n' is 'arina'.
'oc'+'arina'='OCARINA'
(Other definitions for ocarina that I've seen before include "Toy flute" , "Simple wind instrument" , "Toy-like wind instrument" , "source of music" , "Egg-shaped type of flute" .)