"Kid A" has been described as a work of electronica, experimental rock, post-rock, alternative rock, post-prog, ambient, electronic rock, art rock, and art pop. Though guitar is less prominent than on previous Radiohead albums, guitars were still used on most tracks. "Treefingers", an instrumental ambient track, was created by digitally processing O'Brien's guitar loops. Many of Yorke's vocals are heavily modified by digital effects; for example, his vocals on the title track were simply spoken, then vocoded with the ondes Martenot to create the melody.