Found this on Fark today:
Just awesome. The fleeting glimpses of the mechanism are pure gold. And the most impressive part? I'm not sure I knew you could do a glissando on a Mellotron.
Something about hearing this thing in action makes me very, very sad. But then I smile when I think that I expect the player's clothes to fly off Jones-style when he turns around to grin at the camera at the end.