Richard D. James has stated in interviews that the sounds in this music were inspired by lucid dreams, and that upon awaking, he would attempt to re-create the sounds and record them. He claimed that he has natural synaesthesia, which contributed to this album.
Volume II originally consisted of 25 songs, all untitled except for the song "Blue Calx." Every song matches with a specific photograph taken by James himself (except for a solid blue emblem representing the first track of the second CD, "Blue Calx"). The graphics are part of an encoded track-listing system that uses circles and pie diagrams—present in varying forms among the different releases—to represent each track (it may even be the case that the diagrams themselves are the actual track names). The lack of written titles for the tracks on this release provided impetus for fans of the album to come up with their own. Officially, however, the songs are still referred to by their track numbers. The most widely accepted track names are below:
|04||[hankie]||04:31||1-04||/||A-4 (Warp CD only, not the Sire edition)|
|06||[mould] aka [mold]||03:27||1-06||/||B-2|
|07||[ropes] aka [curtains]||08:42||1-07||/||B-3|
|08||[blur] aka [circles]||05:02||1-08||/||B-4|
|12||[white blur 1] aka [steel plate]||02:37||1-12||/||C-4|
|15||[shiny metal rods] aka [metal grating]||05:29||2-03||/||D-3|
|16||[grey stripe] aka [windowsill]||04:38||2-04||/||D-4|
|17||[z twig] aka [b+w stripes]||02:01||2-05||/||D-5|
|18||[windowsill] aka [siding nails]||07:13||2-06||/||E-1|
|19||[stone in focus] aka [wall-to-wall carpet] aka #19||10:05||-||/||E-2 (vinyl only — see Notes)|
|20||[hexagon] aka [corrugated tubing]||05:50||2-07||/||E-3|
|22||[spots] aka [leaves]||07:03||2-09||/||F-1|
|24||[white blur 2] aka [rusty metal]||11:21||2-11||/||F-3|
|25||[matchsticks] aka [b+w stripesII]||05:36||2-12||/||F-4|
The names for the tracks listed, as aforementioned, are interpretations of the photographs on the labels for the vinyl copies and inlay for the double CD release. On the Sire Records (US) editions, various photos were altered, either by showing unblurred photographs or by changing the image altogether. The image representing "[stone in focus]" was removed entirely on the US version, leaving behind an empty white box. The image for "Blue Calx", it being the only explicitly named track, is a blue box that reads "Blue Calx".
"Blue Calx" originally appeared on the Applied Rhythmic Technology compilation album The Philosophy Of Sound And Machine under the artist name Blue Calx, which was released in cooperation with Rephlex Records.
The front cover for this album features the textual Aphex Twin logo that was used on the earlier Xylem Tube EP, albeit in a broken, incomplete form.
The album is referenced by name in the song Pretentious Jenny by band Visually Impaired Placenta.
Track number 3, "rhubarb" was used as part of the soundtrack for a film used by the BBC on Digital TV test transmissions. Also, "rhubarb" and "stone in focus" are featured several times in the animated flash series Salad Fingers and Spoilsbury Toast Boy, respectively, both of which are by animator David Firth.
"Rhubarb" "Curtain" "Window Sill" and "Radiator" were featured on a BBC Documentary about the philosophy of "Time".
"Shiny Metal Rods" was used in a "Saab" Commercial and in a channel 4 advertisement for a TV programme.
Cover versions of “Blue Calx” and "Cliffs" played on acoustic instruments by the Western classical new-music ensemble Alarm Will Sound appeared on its album Acoustica—an album of Aphex Twin pieces re-scored for chamber ensemble.