The Radiohead fan site At Ease has reported that the band will be releasing a 12-inch vinyl single featuring two unreleased songs – "The Butcher" and "Supercollider" – for Record Store Day on April 16th. The official number of copies that will be produced is unknown, but the site says that it may be limited to 2,000 copies per territory. Either way, the single will be one of the most highly sought-after new releases for the annual event, which is designed to drive music fans to brick-and-mortar record shops.
The song "Supercollider" is already known to hardcore Radiohead fans, as it was performed at a few stops on the band's 2008 tour for In Rainbows. Here is a video of Thom Yorke playing the song by himself on piano at a Dublin gig. Given how much Radiohead songs can transform from early live performance to finished studio recordings, the version of "Supercollider" that will be on this single could be very different.
UPDATE: According to the official Record Store Day Twitter feed, this Radiohead single will only be available at record shops in the United Kingdom.