Please can someone help me with the music history question below?

Discuss the role of Deep Purple, Led Zeppelin, Black Sabbath and Alice Cooper in regard to the formulation of heavy metal’s fundamental musical ingredients and basic philosophy.Include the following points: Genealogy, including the role of the blues and psychedelic music; The appropriation of clical music; Metal’s main sonic features, including instrumentation, the function of timbre, and the treatment of dissonance; Lyrical content and the role of gothic imagery and fantasy.