In the Vosse interview he talks about The Elements. He says it had 4 parts,
"For example, he was doing a four part suite called "The Elements", and the fire section of its was all done with percussion instruments. It was like Stravinsky. It was beautifully done, and lasted about two minutes. You've heard all about that thing, with the tape and the fire destroying it. Well that happened, but it didn't mean anything. But at the same time he did that, he took the tail end of "Wind Chimes" - which the way it was originally recorded, was again much more beautiful than on Smiley Smile - and he had a minute and a half tag on it where he took a stand-up tack piano and a grand piano and a track at a time did little music-box overdubs; and then he went in and mixed them with different echoes on different channels into...I've never heard anything like..."
Could he be saying that part is Air? Maybe, it's not clear if he means to relate the two tracks.
That bit rang a bell - took me a while, but I found it:
Teen Set 1966
"It is a balmy afternoon in Hollywood.
Brian Wilson comes into Studio 3 at Western Recorders for an overdubbing session.
In the booth his personal eight-track tape machine is ready to roll (
bit of artistic license here ).
In the studio an old, upright honky-tonk piano and Brian's beautiful black grand piano wait under the microphones (
again, nonsense).
"I have an idea, I'm not sure exactly how this is going to work, but we'll try it."
Brian goes to his piano and signals Chuck, the engineer to roll the tape. He plays a simple music box melody. The tape is run back. On a second track he adds some tinkles on the honky-tonk piano.
For about half an hour Wilson goes over the same piece, filling the eight tracks with counterpoints, syncopated gates and notions.
"OK, let's hear it."
Wilson in the control room close to the centre speaker, listens to the playback. He rushes to the board and supervises the throwing of switches and turning of knobs. More echo on the third track, a touch of reverb on the second honky-tonk overdub, this track dry and the other with more highs. Something happens to the sounds; they change, they move around and are transformed into a work of sheer beauty.
Everyone in the booth has seen and heard the entire process."
Sounds awfully like the "Bicycle Rider" theme to me.
Sounds like the tag to the Smile Wind Chimes to me.