You may recall seeing Michael’s appearance on The Ellen DeGeneres Show last fall when she surprised him with a Gibson guitar, courtesy of Guitar Center, that would be signed by musical guests of the show and then auctioned off to benefit Parkinson’s research. The day has finally come with the auction kicking off last night on eBay!

The cherry red Gibson guitar — a Gibson Custom 1959 ES-335 Historic Dot Reissue, to be exact —  was signed by Madonna, Gwen Stefani of No Doubt, Brandon Flowers of The Killers, Rob Thomas of Matchbox Twenty, Jakob Dylan of The Wallflowers, Ellen DeGeneres, and of course, Michael J. Fox himself.

The auction will go until Sunday, September 22, so get going and place your bid today. The winning bid will take home the guitar (retail value of $4,999!) and support Parkinson’s research toward a cure.

And don’t forget to share the news with your musical friends on Facebook and Twitter (social media friendly link: http://bit.ly/ellenebay).