Singer's block on single about sex (8)
I believe the answer is:
baritone
'singer's' is the definition.
(baritone is a kind of singer)
'block on single about sex' is the wordplay.
'block on' becomes 'bar' (bar is a kind of block. I am not sure about the 'on' bit.**).
'single' becomes 'one' (I've seen this before).
'about' means one lot of letters go next to another.
'sex' becomes 'it' (a common euphemism).
'one' after 'it' is 'itone'.
'bar'+'itone'='BARITONE'
Can you help me to learn more?
(Other definitions for baritone that I've seen before include "Second lowest male singing voice" , "Male singer in boater, strangely" , "One who can sing" , "Male singer between tenor and bass" , "solo voice" .)