Before Metallica was one of the biggest acts in the world, they were opening for Ratt at a roller rink. This revelation came out when Ratt vocalist Stephen Pearcy took to Twitter to address someone asking him if this was true. Pearcy showed the flyer for the show, saying he and the band got along well and that he has nothing but respect for Metallica.
This being 1982, Metallica's lineup was James Hetfield and Lars Ulrich alongside (probably) Dave Mustaine and definitely Ron McGovney. McGovney chimed in on Twitter, saying people were skating while the show was going on!
The rest of the lineup for the bill included Y&T billed above Metallica, who had just formed one year prior, and then Yngwie Malmsteen performing as Rising Force even though that album wouldn't come out until 1984, and a band called Victory.