I heard a story about metallica today. 
Is Metallica your favorite band? I know that it was formed in 1981.
It is not, I think they are a bunch of babies who cry about the internet. 
It was formed by Ulrich, one of the best drummers out there.  Metallica is not mine either but I have read a lot about different types of bands, including Metallica.
why did they make music?
Metallica musicians likes aggressive, fast and loud instruments.  I don't.
and do they make money by doing that? are they people?
Metallic members consist of Guitarist Dave Mustaine and bassists Ron McGovney, Cliff Burton and Jason Newsted.  I think they are people.