Messiaen, lots of serialist works, and many contemporary pieces in general are probably the hardest to memorize, if it is possible at all. It makes Romantic and everything before easy to memorize.
but, atonal 20th century works aside, what other pieces from the mainstream repertoire are difficult to memorise?
A lot of Godowsky is easy to memorise approximately, very hard to memorise accurately.
Indeed - try memorizing the Passacaglia (no, Richard, I don't mean you, I'm talking to the others!); even Carlo Grante and the Godowsky expert Charles Hopkins (1952-2007) admitted that this is immensely hard to memorise.Best,Alistair
I find Schumann hard to memorize because it's just so illogical.
Generally 20th Century works because our brain isn't used to organizing the music in an orderly fashion than in the Classical Period.Scriabin's sonatas are a great example.
Scriabin's sonatas are organised in a highly orderly fashion, and are mostly Classical in construction. Medtner's are too, but I find his work hard to memorise, while Scriabin's relatively easy. Other people have told me as much too, but none of us can figure out why.
Most of Albeniz "Iberia," I think, is a major pain to memorize. All those infinite numbers of inner voices wandering about almost aimlessly and rarely repeating a consistent pattern."El Puerto" really drove me nuts.
Another pianist once told me that, having spent a long time learning and memorising the splendid Op. 52 No. 2 sonata, he was dismayed and somewhat shocked to discover just how rapidly much of it evaporated from the memory following his first performance of it. I have no idea why this should be, either. What I do know is that almost all of Medtner's work is worth the effort; surprisingly little of it is much below his best, I feel.Best,Alistair