What if I don't get it? Blonde moment.
From the Mixdown website:
Carnival of Light” has not yet appeared on any release, either official or a bootleg recording. In 1996 McCartney tried to release the track on the compilation album The Beatles Anthology 2, but George Harrison voted to reject it. According to McCartney, the reason was that “he didn’t like avant garde music” and referred to avant garde as ‘avant garde a clue’ (“haven’t got a clue”). George Harrison had also created avant-garde music as a solo composer (in 1969 he released an experimental album using the then new Moog synthesizer called Electronic Sound), and dabbled in the avant-garde with a couple of his Beatles compositions.