Listen to Led Zeppelin's Unreleased 'Physical Graffiti' Recordings

Recordings Led Zeppelin made as they were creating 1975's Physical Graffiti will be available at auction next month.

RR Auctions, which is based in Amherst, New Hampshire, says several songs on the tapes that are up for grabs differ structurally from their officially released versions.

As you can hear from the examples below, the band re-recorded guitar and vocal parts on some of the songs. In several cases, they used only John Bonham's drum tracks and overhauled everything else.

The tapes are part of the Ron Nevison collection, which also is auctioning rough mixes of Bad Company's debut album and four songs from Eric Clapton's live 1973 release, Eric Clapton's Rainbow Concert, plus recordings by the Who, Ozzy Osbourne and more.

Rolling Stone reports that audio engineer Ron Nevison recorded the drum parts for "Kashmir," which was then called "Driving to Kashmir." John Paul Jones was late to the session, so Jimmy Page worked out the riff with Bonham. "Driving to Kashmir," as it appears on these tapes, is totally instrumental.

RR Auctions is offering pieces of the Ron Nevison Collection as part of its "Marvels of Modern Music" auction. The auction will take place March 13 through 20.