Unreleased studio mixes of Led Zeppelin's 1975 album Physical Graffiti are set to hit the auction block in March (14).

Demo recordings of classic songs such as Kashmir, Custard Pie and In the Light will go up for sale at the Marvels of Modern Music event, which will be held by bosses at RR Auctions in New Hampshire.

Bidding for the recordings start at $300 (£187.50).

Other items also featured in the auction include unfinished versions of Bad Company's self titled debut album, songs from Eric Clapton's Rainbow Concert, a master copy of Elton John's Pinball Wizard from the movie Tommy, a signed copy of the Beatles' Twist and Shout Ep, and the cape from Elvis Presley 1973's Tv special Aloha From Hawaii.