Question

Mick fleetwood is best known as the cofounder and played the drums for the rock band fleetwood mac. what is wrong with the sentence?

Answer 1

it lacks parallel structure

Answer 2

I believe that what is wrong with the sentence is that it never says what he was the cofounder of - the order of the words in the sentence is a little funky. It should be rewritten like this:
Mick Fleetwood is best known as the cofounder of the rock band Fleetwood Mac, where he played the drums.