Swing music introduced by kid on the radio (7)
I believe the answer is:
trapeze
'swing' is the definition.
(trapeze is a kind of swing)
'music introduced by kid on the radio' is the wordplay.
I cannot really see how this works, but
'music' could be 'rap' (musical genre) and 'rap' is present in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found within the answer.
This explanation may well be incorrect...
(Other definitions for trapeze that I've seen before include "Swinging crossbar" , "Circus feature" , "Swinging acrobat's bar" , "Flying bar for acrobatics" , "Seat on end of ropes" .)