At the time I had a good friend who wasvery musically aware - used to see every gig on a Zappa tour in the 60's and 70's.

he was also a big Pistols fan. He saw several of their performances and rated them very highly musically. said they were very tight and together. He said the tales of musical ncompetence were no more than that - stories fed to the newspapres and oft repeated by people too ignorant to know the difference.