Music producer's boss claiming £50 (5)
I believe the answer is:
cello
'ps50' is the definition.
I can't judge whether this definition defines the answer.
'music producer's boss claiming' is the wordplay.
'music producer's' becomes 'll' (I can't justify this - if you can you should give a lot more credence to this answer).
'boss' becomes 'ceo' (chief executive officer).
'claiming' is an insertion indicator.
'll' going into 'ceo' is 'CELLO'.
Can you help me to learn more?
(Other definitions for cello that I've seen before include "Jacqueline du Pre's instrument" , "big fiddle?" , "Musical instrument like large violin held between knees" , "Bass stringed instrument" , "Large stringed instrument" .)