A single male part backed by composer (8)
I believe the answer is:
bachelor
'a single' is the definition.
(I've seen this before)
'male part backed by composer' is the wordplay.
'male part' becomes 'role' (eg a theatrical role. I am not sure about the 'male' bit.).
'backed' says the letters should be written in reverse.
'by' means one lot of letters go next to another.
'composer' becomes 'bach' (Johann Sebastian Bach).
'role' reversed gives 'elor'.
'elor' put after 'bach' is 'BACHELOR'.
Can you help me to learn more?
(Other definitions for bachelor that I've seen before include "He's not married" , "he has no ties" , "Single person" , "Single man" , "Unmarried male" .)