Initial signature sound by two family members and one of The Quarrymen perhaps
I believe the answer is:
stonemason
'initial signature' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'sound by two family members and one of the quarrymen perhaps' is the wordplay.
I cannot quite see how this works, but
'sound' could be 'tone' (tone is a kind of sound) and 'tone' is present in the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is found in the answer.
'one' could be 'a' and 'a' is present in the answer.
'of' could be 'o' and 'o' is located in the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for stonemason that I've seen before include "Chiseller" , "manual worker" , "Architectural carver" , "Building worker" , "One working with, eg, granite" .)