Company backed opera tunes after receipt of new instruments (8)
I believe the answer is:
ocarinas
'instruments' is the definition.
(ocarina is a kind of instrument)
'company backed opera tunes after receipt of new' is the wordplay.
'company' becomes 'co' (abbreviation).
'backed' says the letters should be written backwards.
'opera tunes' becomes 'arias'.
'after receipt of' means one lot of letters goes inside another (some letters are received by others).
'new' becomes 'n'.
'co' written backwards gives 'oc'.
'arias' going around 'n' is 'arinas'.
'oc'+'arinas'='OCARINAS'
(Other definitions for ocarinas that I've seen before include "Small wind instruments with egg-shaped bodies" , "Can I soar above the musical toys" , "musical instruments" , "No air sac, strangely, on the wind instruments" , "MUSICAL INSTRUMENT" .)