So predecessor briefly thanks said composer who accepts a lot? (8)
I believe the answer is:
fatalist
'who accepts a lot?' is the definition.
(someone who accepts their fate or lot in life)
'so predecessor briefly thanks said composer' is the wordplay.
'so predecessor' becomes 'fa' ('so' comes before 'fa' in 'do re mi so fa la ti').
'briefly thanks' becomes 'ta' (short way of saying 'thank you').
'said composer' becomes 'list' (I can't justify this - if you can you should give a lot more credence to this answer).
'fa'+'ta'+'list'='FATALIST'
Can you help me to learn more?
(Other definitions for fatalist that I've seen before include "One submitting to destiny" , "Person who accepts life as it comes" , "One who accepts whatever happens as inevitable" , "One who accepts events as inevitable" , "One with a submissive attitude to events" .)