Listen to Led Zeppelin’s unreleased demo tapes for Physical Graffiti

Led Zeppelin with jet

Led Zeppelin with jet

Next month, a rare batch of previously unreleased Led Zeppelin recordings will hit the auction block. The tracks were originally recorded during the sessions for 1975′s double album, Physical Graffiti.

Included in the collection are alternate mixes of “Trampled Underfoot”, “Driving to Kashmir”, “Custard Pie”, “In The Light (Everyone Makes It Then)”, “Swan Song Part 1″, and “Swan Song Part 2″. According to the company behind the auction, RR Auction, many of these takes are structurally different — some even completely instrumental – from those on the album’s final version.

As Rolling Stone notes, the tracks were recorded at Ronnie Lane’s Mobile Studio, one of the first ever mobile studios, built by audio engineer Ron Nevison. They’re among the larger Ron Nevison Collection, which is also auctioning songs from Eric Clapton’s Eric Clapton’s Rainbow Concert LP and early mixes of Bad Company’s eponymous debut.

Below, listen to a short sampler of the unreleased Led Zeppelin recordings and a 30-second clip of “In The Light”.

The RR Auction, dubbed Marvels of Modern Music, runs from March 13th through March 20th. Head here for more information.