Bravo! Jason’s playing musical instruments! (6)
I believe the answer is:
banjos
'musical instruments' is the definition.
'banjos' can be an answer for 'instruments' (I have seen 'Stringed instruments ' mean 'banjos' so perhaps 'instruments' could also mean 'banjos'). I am not sure about the 'musical' bit.
'bravo jason's playing' is the wordplay.
'bravo' becomes 'b' (phonetic alphabet: alpha, bravo, charlie etc.).
'playing' is an anagram indicator.
'jason' is an anagram of 'anjos'.
'b'+'anjos'='BANJOS'
Can you help me to learn more?
(Another definition for banjos that I've seen is " Stringed instruments".)