Three quavers by singer good, on the whole (10)
I believe the answer is:
altogether
'on the whole' is the definition.
(synonyms)
'three quavers by singer good' is the wordplay.
'three quavers' becomes 'ether' (I can't explain this - if you can you should give a lot more credence to this answer).
'by' says to put letters next to each other.
'singer' becomes 'alto' (type of singing voice).
'good' becomes 'g' (abbreviation).
'alto'+'g'='altog'
'ether' after 'altog' is 'ALTOGETHER'.
Can you help me to learn more?
(Other definitions for altogether that I've seen before include "Quite" , "Entirely" , "nude in this" , "special to get Hermes trousers" , "totally" .)