'Reckoner' was written in late 2006 or early 2007, and is not to be confused with another song that used to have the same title for several years and was finally released in 2009 under its initial title: 'Feeling Pulled Apart by Horses'.
However, both songs are strongly connected. 'Feeling Pulled Apart by Horses' (under the title "Reckoner") was part of the 2005/2006 sessions for what would become In Rainbows and was even considered for the 2006 tour, though it remained unplayed. After that tour had ended, the band began sessions with Nigel Godrich, and during this period an attempt was made to write a new section for the song. This new section then took on a life of its own and became a separate song, which was released on In Rainbows as 'Reckoner'.
However, both songs are strongly connected. 'Feeling Pulled Apart by Horses' (under the title "Reckoner") was part of the 2005/2006 sessions for what would become In Rainbows and was even considered for the 2006 tour, though it remained unplayed. After that tour had ended, the band began sessions with Nigel Godrich, and during this period an attempt was made to write a new section for the song. This new section then took on a life of its own and became a separate song, which was released on In Rainbows as 'Reckoner'.
In the autumn of 2006, the band continued working on the "old version" of 'Reckoner' with Nigel Godrich, and soon the idea came up to write another part for the song. This new part then took on a life of its own and turned into this song, and the band gave up trying to record the old song for this album. In late november the phrase "In Rainbows" appeared on the start page of radiohead.com, and in december the band worked on this new song at Nigel's London studio at The Hospital in Covent Garden.
The album title phrase "in rainbows" can be clearly heard in this stereo extraction from the released version of 'Reckoner':
The album title phrase "in rainbows" can be clearly heard in this stereo extraction from the released version of 'Reckoner':
On july 11th 2008, Thom posted a piece related to 'Reckoner' on his page at w.a.s.t.e. central. It was titled "robot reckoner celeste", and the info embedded in the mp3 suggests it is a sketch, probably something he or Jonny did on a laptop. In a post at his page from the same day he briefly mentions finding it:

This piece can also be put onto the middle of 'Reckoner', as it fits harmonically and has the same length as the break of the song. It is possible that this piece was a sketch of an idea for the middle of the song, which ultimately wasn't used:
A more cut up version had appeared more than a year before already, though it wasn't known that it had anything to do with 'Reckoner' at that time. On april 4th 2007 the following clip appeared in the Hodiau Direkton section of radiohead.com, titled 'Quiet Day at the Office'. It shows distorted footage taken at Tottenham House in october 2006 and features the piece as the soundtrack. It dates the sketch to early 2007 at the latest:
This recording again fits perfectly into the middle of 'Reckoner', and musically it even sounds better than when the original sketch is overdubbed. It is possible that the sketch was messed up a bit to make it sound better before the idea was entirely abandoned. This is a reconstruction of what the section might have sounded like:
On november 9th 2007, the song was played live to an audience for the first time during the Thumbs_down webcast:
On april 2nd 2008, the band did an excellent version of 'Reckoner' for Nigel Godrich's From The Basement. The program was aired on May 3rd 2008 on VH-1, and later uploaded by the band to YouTube:
In Rainbows | may 2008 | june 2008 | july 2008 |
In Rainbows | august 2008 | october 2008 | march 2009 | august 2009 |