The German power metal band that released Keeper of the Seven Keys, Part I was Helloween.
Helloween formed in Hamburg in 1984 and helped shape the fast, melodic style often called European power metal. Keeper of the Seven Keys: Part I was the band’s second studio album, released by Noise Records on May 23, 1987.
The album introduced vocalist Michael Kiske, who joined a lineup featuring Kai Hansen, Michael Weikath, Markus Grosskopf, and Ingo Schwichtenberg. Songs such as “Future World” and “Halloween” helped establish Helloween’s combination of rapid guitar work, high-register vocals, bright melodies, and extended song structures.
The band had originally wanted Parts I and II to appear as a double album, but the record label required separate releases. Part II arrived in 1988. Gamma Ray is connected to the story because Hansen later founded that band, but it did not release this album.