Just went through a list of Beatles songs while answering another thread. Shock! There are songs I've never heard. Madman and Watching Rainbows.
Madman songs like an early version of Mean Mr Mustard. Before a considerable rewrite, but the basic rhythm and simple major key feel seems to have survived.
I've just looked here. Holy @$%^, there are more of them. I used to collect Beatles ... 'additional material' back when it was a matter of buying discs from grubby stalls in markets. I didn't buy many Let it Be session discs as the first few I got were endless retreads of the already released materials plus a few covers. I've missed out a lot. I noticed a youtube video of 'The Palace of the King of the Birds' which I presumed was a falsely attributed Beatles song, but it checks out. Was that written when it was mooted that The Beatles. There looks to be more, and with youtube, it's easy to find these tracks.