Are you a fan of rock opera at all? I love it! If you don't know what it is, it's basically rock music songs with lyrics that relate to a common story.
Actually yes I am. And also Metal symphony
One thing I really like about rock opera is how they use various character roles within the song lyrics. It's a pretty common storytelling device used in the genre.
I wonder what the most popular is?
I do know that Colin Fleming from "The Atlantic" identified "The Story  of Simon Simopath" by the British psychedelic band called Nirvana as being one of the first recorded rock opera. They were pretty big!
I'd say. My favorite is The Wall by Pink Floyd
I'm a big fan of "Mad Birds of Prey (A Mini-Opera) which is a long suite recorded by Montreal's Influence in 1967. IT closed out their sole album, which was released in January 1968.
Is Jesus Christ Superstar considered a rock opera? 
Yes indeed. It is a musical that started out as a rock opera album before its Broadway debut in 1971.
Phantom has a similar feel as well