By 1973's 'Houses of the Holy,' Led Zeppelin were no longer psychedelic blues-rock warriors. Sure, that was one page in their stylistic playbook, but with each subsequent album, their aspirations grew wilder and more unpredictable. 'Houses of the Holy' is arguably the band's most eclectic album, branching into funk and art-rock balladry and metallic prog.

The No. 14 track on our list of the Top 50 Led Zeppelin Songs, 'Over the Hills and Far Away,' the album's anthemic lead single (and the first track the band previously debuted on-stage), falls into the latter category, building from a tender -- yet deceptively complex -- acoustic opening passage to a towering blast of full-band propulsion to a moaning Jimmy Page guitar solo, all before circling back again.

It's a unique item in the Led Zep catalogue: one of their most technically challenging tracks as well as one of their catchiest. Throughout all the neck-breaking dynamic and textural shifts, John Bonham and John Paul Jones keep the rhythms swinging and funky, while Robert Plant delivers one of his most passionate and melodic vocal performances. Peaking at No. 51 on the Billboard charts, 'Over the Hills' wasn't exactly a smash single, yet it remains a staple on classic-rock radio--arguably the band's most empowering windows-down anthem. Just try driving to it without pounding on your steering wheel...