Depends on your classification of "metal"... I saw Loudness open for Motley Crue on the Theatre of Pain tour. I saw Bon Jovi open for Ratt, and I saw the Ratt-Poison tour. I saw Metallica open for Ozzy's Ultimate Sin tour. Pretty much most of my metal shows were in the 80's. The rest were more like Blue Oyster Cult, Aerosmith, Trixter, Slaughter.... But the heaviest first metal show was probably Metallica opening for Ozzy. They blew Ozzy away, IMO. I think they were touring their MOP album, that was the banner behind them. You almost never saw their faces either, all you saw was hair flying! This was in their better days. I really don't care for much of their music past ...And Justice For All, because they got too mainstream, too whiny, and lately with that Lou Reed collab, too artsy-fartsy!