1978 was one of Judas Priest's finest years, as well as one of the original Black Sabbath's absolute worst.

It was ultimately a transitionary period in the genre, as the marriage of punk's do-it-yourself ethics with metal's musicianship that was pioneered by Motörhead the previous year would truly take off in 1979 with an explosion of new bands.

Metal took an interesting turn in 1977 as it inherited influence from another popular new genre.

You guessed it. 1977 was the year that our beloved punk rock took the U.K. by storm. It was the year of The Sex Pistols, The Clash, The Damned and The Stranglers. Punk was essentially rock music stripped to its barest elements and given a major dose of social angst and unrest. It arised in resistance to the "overproduced arena rock" of the day, which, in their minds, included heavy metal.

From their first release in 1970 to Sabotage in 1975, Black Sabbath were the undisputed kings of heavy metal. That label became disputed in 1976 when Judas Priest released an album that was far superior in every way to Black Sabbath's offering of the same year.

After a string of five commercially and critically successful albums in the short span of four years, the cracks in Black Sabbath's armor were showing.

The Birmingham natives found themselves embroiled in a legal battle with their former management - who had allegedly been embezzling money from the band. Also, frontman Ozzy Osbourne and guitarist Tony Iommi became increasingly confrontational over the direction of the band, with Ozzy constantly complaining about Tony's "studio production obsession." To make matters even worse, Sabbath's legendary drug abuse was in overdrive, as the band was getting messed up on multiple substances every single day.