Uriah Heep (band) recording of the album, drummer Alex Napier was replaced by Nigel Olsson, recommended to Byron by Elton John. The debut was not popular with rock critics (especially in the USA where "Rolling Stone" reviewer Melissa Mills infamously promised to commit suicide "if this band makes it") but in retrospect the attitude towards it changed. "Those unfamiliar with Uriah Heep may want to try out "Demons and Wizards" or a compilation first, but anyone with a serious interest in Uriah Heep or the roots of heavy metal will find plenty to like on ..."Very 'eavy ...Very 'umble"," advised critic Donald A.
Heavy metal music tone, typically in the bass range, during which at least one foreign (i.e., dissonant) harmony is sounded in the other parts. According to Robert Walser, heavy metal harmonic relationships are "often quite complex" and the harmonic analysis done by metal players and teachers is "often very sophisticated". In the study of heavy metal chord structures, it has been concluded that "heavy metal music has proved to be far more complicated" than other music researchers had realized. Robert Walser stated that, alongside blues and R&B, the "assemblage of disparate musical styles known ... as 'classical music has been a major influence