In the early 1980s Helloween stood alongside Blind Guardian as one of the early European power metal bands. Walls of Jericho (1985) was a genre defining album and remains an exemplar of power metal. After that, they recruited a new vocalist, Michael Kiske, and the new album, Keeper of the Seven Keys, Part 1 (1987) consolidated the success of their debut. The third album Keeper of the Seven Keys, Part II (1988) is considered to be the seminal Helloween release.
The focus of the band shifted for 1991’s Pink Bubbles Go Ape, and saw the band assume a comedic persona and adopt a poppier style. The album failed to sell, but undaunted they released Chameleon in 1993, varying their signature style significantly with the addition of acoustic guitars, choirs of children and country music. The fans voted with their wallets and the album failed miserably. The resultant in-fighting resulted in the departure of several of the members, and by 1994 the band was several members short, without a record contract and playing to half-empty venues.
When they returned it was with a vengeance, Master of the Rings (1994) and its follow-up, Time of the Oath (1996) marked a return to form and the relieved fans showed their appreciation. Helloween learned their lesson from the disaster of Chameleon and subsequent releases remained true to the power metal origins – if they veered at all, it was into heavier territory, with The Dark Ride (2000).