Saw show on Rhythm & Blues (7)
I believe the answer is:
proverb
'saw' is the definition.
(a saw can mean a proverb or maxim)
'show on rhythm blues' is the wordplay.
'show' becomes 'prove' (proving is a kind of showing).
'on' is a charade indicator (letters next to each other).
'rhythm blues' becomes 'rb' (this might be a standard abbreviation which I don't know about).
'prove'+'rb'='PROVERB'
Can you help me to learn more?
(Other definitions for proverb that I've seen before include "Saying of great truth" , "Adage, pithy saying" , "encapsulate wisdom" , "Traditional saying" , "Maxim" .)