Rock star, short and dumpy, toting machine gun Ringo discharged (4,6)

'rock star short' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.

'dumpy toting machine gun ringo discharged' is the wordplay.
I cannot quite understand how this works, but
'gun' could be 'uzi' (military weapon) and 'uzi' is present in the answer.
'dumpy' could be 'squat' (both can mean short and stocky) and 'squat' is found within the remaining letters.
This may be the basis of the clue (or it may be nonsense).

'and' acts as a link.

Can you help me to learn more?