Wonder what your signed Beatles LP is worth, or what that original Rolling Stones tour poster you ripped of the wall in the ’70s might sell for? Here’s your chance to find out.

Specialists from Bonhams Auction House are teaming up with the Hard Rock Cafe in London to host the first “Antiques Rockshow;” they will value “any genuine piece of music history,” according to a Hard Rock Cafe news release. The event will run from 11 a.m. to 4 p.m. local time May 18, 2011.

Those who participate in the Rockshow also may have the option to add their items to Bonhams’ upcoming Entertainment Memorabilia Auction, which will begin at 1 p.m. local time June 29, 2011, at the firm’s Knightsbridge location in England. No further details are available about the sale at this time.

The London Hard Rock Cafe celebrates 40 years in business this year. The first in what went on to become a worldwide chain, the London Hard Rock opened June 14, 1971. It also is home to  the first-ever piece of memorabilia donated to the Hard Rock Cafe: Eric Clapton’s Lead II Fender, which was originally donated to reserve a space at the busy bar.