Silly trumpeter who trundled off during song caught on mic (5)
I believe the answer is:
nelly
'silly' is the definition.
(I've seen this before)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for nelly that I've seen before include "Fool" , "Chump" , "Life" , "Let not poor - starve (Charles II)" , "See 11" .)