Dave Mustaine (MEGADETH) will join METALLICA on stage tonight (Saturday, December 10) at the fourth and final intimate show at the Fillmore as part of the week-long celebration of its 30th anniversary as a band for fan club members only. He will play five songs with METALLICA: "Hit The Lights", "Metal Militia", "Phantom Lord", "Jump In the Fire" and "Seek And Destroy".Mustaine, who was one of the original members of METALLICA, was fired from the band by drummer Lars Ulrich in 1983. He was replaced by Kirk Hammett and went on to form MEGADETH and achieve worldwide success on his own. In an interview with Revolver magazine conducted earlier this year, Mustaine was asked what he remembers about writing music with METALLICA while he was in the group. "I had always called us, as a group, the 'Four Horsemen,'" he said. "Before I was in METALLICA, I really loved this band called MONTROSE, and their guitarist was Ronnie Montrose. He went on to form a band called GAMMA. One of their records [1980's 'Gamma 2'] had a shark fin cutting through the grass, which I thought was so awesome. Anyway, he had a song on there called 'Four Horsemen' that I did with my band PANIC, which I was with before METALLICA. So when I joined METALLICA, I had the song 'Mechanix', which I wrote, and 'Four Horsemen' was a suggestion of mine to do 'cause we were doing cover songs. So that had planted the seed with James [Hetfield, METALLICA frontman]. And one day when we were coming to rehearsal, Lars had just said something about slowing down my song, 'Mechanix'. I had just gotten to the studio with Cliff [Burton, METALLICA bassist], and we had been listening to LYNYRD SKYNYRD, and I was being a jerk, so I played 'Sweet Home Alabama' instead of 'Mechanix', and that’s basically the middle part of what would become METALLICA’s 'The Four Horsemen'." Regarding what his favorite METALLICA song is, Mustaine said, "I had to do a lot of coming to terms with myself in order to listen to METALLICA. Before, whenever I heard them, it triggered me in my mind to get up on my soapbox and spit out complaints of what had happened to me. And then once I finally realized, 'Dave, you're lucky, you're blessed, you're in a great band, you're in another great band.' I finally just said, 'You're missing it.' "And I remember hearing this song when I was talking to Lars once and telling him this is my favorite song off the 'Black Record.' And he goes, 'Really? Fuck, man.' It was 'The Unforgiven'. I liked it because I thought this was really the first time I've ever really heard James [Hetfield] sing. He had sung before, and he was a great singer. But that was the first time I ever heard him really, really sing."