Rock On saw Humble Pie establishing the heavy blues/rock sound they became famous for, led in no small part by their new manager, Dee Anthony, after the collapse of Andrew Loog Oldham's Immediate Records.

[3] In the latter part of the year, after their live album Performance Rockin' the Fillmore was mixed, and shortly before it was released, he left the band[3] to pursue a solo career, and take his music in a more acoustic direction.

Singer and guitarist Steve Marriott turned the production into a studio party of sorts, featuring numerous guest performers from the world of blues and soul.

Distinguished performers such as PP Arnold, who Marriott knew very well from his Small Faces days, Doris Troy who had a U.S. hit in the early 1960s with her own self-composed song "Just One Look" (later covered by The Hollies), and Claudia Lennear (who had sung backing for artists such as Joe Cocker, Freddie King and Gene Clark), were featured on this album.

"Strange Days" is a blues rock song in which Marriott's powerful vocals soar as close to a live performance as any on this album.