1) Judas Priest
Judas Priest is actually one of the few bands that could be on this list twice. They were initially a blues band and actually took their name from a Bob Dylan song. They looked and sounded more like flower children on their first album, Rocka Rolla, and there was still prog/folkiness on Sad Wings of Destiny as they continued to find their sound. By the time 1980 rolled around, Halford was one of the best metal singers in the genre and the guitar harmonies of Glenn Tipton and K.K. Downing were the stuff of legend.
However, in the mid-80s, Downing and Tipton discovered guitar synths, and Turbo and Ram it Down were the band at their commercial peak, but not in a good way. While there will probably be an In Defense of Their Good Name coming for Turbo from one of us eventually, it was a low point for heaviness. However, 1990’s Painkiller was a creative revival for the band, especially based off it’s title track, which is almost speed metal. With Redeemer of Souls coming soon, the band look to cap off their 40th year with another heavy record.