The song opens with Beck using volume swells on an overdriven guitar to simulate a train whistle and the band launches into the song with rhythm guitarist Chris Dreja, bassist Paul Samwell-Smith, and Beck following the riff from the Rock and Roll Trio's song. Two combined takes of Keith Relf's vocal, with some differences in the lyrics, come in after twelve bars. Following the vocal section, the rhythm changes to a shuffle and a 12-bar harmonica and guitar bridge sets the stage for Beck's first solo. After returning to the original rhythm for another double-tracked vocal section, a brief "rave up"-style section precedes Beck's second solo. A rave up is used to describe a middle instrumental section of a song, when the beat shifts into double-time and the instrumental improvisation gradually builds to a climax. It was part of the Yardbirds' signature sound and "represent some of the earliest psychedelic blues-rock, antedating Jimi Hendrix and Cream", according to Birnbaum. Beck's second guitar solo, which extends for two 12-bar sections, features an early use of a fuzz-tone distortion effects pedal. Birnbaum describes his work as "incendiary" and "riveting, relatively complex solos". The Yardbirds' rendition became the new standard that subsequent musicians would follow.