Musician perhaps a boastful person? (9)
I believe the answer is:
trumpeter
This clue is a double definition.
'musician' is the first definition.
(I know that trumpeter is a type of musician)
'a boastful person?' is the second definition.
(someone blowing their own trumpet)
'perhaps' acts as a link.
(Other definitions for trumpeter that I've seen before include "Instrumentalist - type of swan" , "one of a band" , "Boastful" , "[SOMETHING FISHY]" , "Elephant perhaps" .)