Under this line-up, they released the Keeper of the Seven Keys albums (1987 and 1988), which established Helloween as a notable heavy metal band and led to the creation of the power metal subgenre.
Sub această linie, au lansat albumul "Keeper of the Seven Keys" (1987 și 1988), care a stabilit Helloween ca o trupă notabilă de heavy metal și a dus la crearea subgenului power metal.