Thanks to everyone for the suggestions! Brilliant (and daunting! π).
I have listened via Spotify to some of the works as suggested, then Spotify did it's random jukebox thing and up popped Claude Debussy. Which I really liked. So I've been listening to him for a bit now.
Tonight I've given some of BartΓ³k's Mikrokosmos a listen and was really surprised! I hadn't realised that it was a series of slowly building piano tutorials with mostly (so far) two different intervals at a time travelling around the, erm, mikrokosmos.
This kind of approach I do already on my bass just for fun, feeling out textures with tensions and release. Right up my street!
I've ordered the definitive book to have a look at what's actually going on. Seems like a fun way to practice reading again and will get me enthusiastically sat at the piano for a change.
I'm going to create a playlist on Spotify with every suggestion so far, so I can go through everything whilst in the car.
I'll try and make it public so others can add to it if they like, similar to the basschat Best Basslines Ever playlist that was popular a few years back (once I work out how it's done! π)
Cheers all!