Singer followed by good number in total (10)
I believe the answer is:
altogether
'in total' is the definition.
(I've seen this before)
'singer followed by good number' is the wordplay.
'singer' becomes 'alto' (type of singing voice).
'followed by' says to put letters next to each other.
'good' becomes 'g' (abbreviation).
'number' becomes 'ether' (anaesthetic, something which numbs).
'alto'+'g'+'ether'='ALTOGETHER'
(Other definitions for altogether that I've seen before include "special to get Hermes trousers" , "Entirely" , "Quite" , "nude in this" , "Completely, in total" .)