
Ritchie Blackmore's guitar solo on Highway Star is a precisely executed Bach-inspired run played at extraordinary speed — one of the first true neo-classical metal solos predating Yngwie Malmsteen by a decade. Blackmore based the solo on a Bach organ piece and executed it with a discipline and technical precision that was unheard of in hard rock at the time. Deep Purple's Machine Head remains one of the greatest hard rock albums ever recorded.
Reference:
TaskLoco™ — The Sticky Note GOAT