I would say it was an 8/10 for me, although it could have been 9. I thought of the wrong answer for the one question. I just misread it and forgot! That’s all right.
This was actually more difficult and esoteric than I was expecting. It should be noted too that while the earliest Beatles release featuring backwards content was indeed Rain, the backwards guitar lead on Tomorrow Never Knows was actually recorded earlier.
Quite true, it was the first to be recorded but was the last track on Revolver as they felt if they put it on first nothing else could follow it. Rain was slowed down by about a half. Most of the guitars notes were recorded "backwards" so when played backwards were in the right order.