Four Tet's (aka Kieren Hebden) excellent Rounds is being re-issued for it's 10th anniversary, and Four Tet share the original version of album cut "Unspoken", which prominently featured a Tori Amos piano part that didn't get cleared in time for inclusion on the album. Hebden tweeted this about the song's release today:
“The first track I made for the album… this version (is) about 12 years old. We tried get the Tori thing cleared for the reissue but still didn’t work out.”
The piano really changes it's parts of the song, seemingly becoming the center of the gorgeous collage of sounds.