Helloween is a German power metal band founded in 1984 in Hamburg, Northern Germany. The band is a pioneering force in the power metal genre, and their second and third studio albums, Keeper of the Seven Keys: Part I and Part II, are considered masterpieces of the genre. Twelve musicians have been a part of the band's line-up in its history, which has consisted of singer Andi Deris, guitarists Michael Weikath and Sascha Gerstner, bass guitarist Markus Grosskopf, and drummer Daniel Löble since 2005.