Who sings except for one note? (8)
I believe the answer is:
baritone
'who sings' is the definition.
I can't tell whether this definition defines the answer.
'except for one note?' is the wordplay.
'except' becomes 'bar' ('bar' can mean 'except' or 'not including').
'for one' becomes 'i' (I've seen this in other clues).
'note?' becomes 'tone' ('tone' can be a synonym of 'note').
'bar'+'i'+'tone'='BARITONE'
Can you help me to learn more?
(Other definitions for baritone that I've seen before include "Male singer between tenor and bass" , "Male voice between bass and tenor" , "One who can sing" , "solo voice" , "Male voice with deep register" .)