Chopin Etudes, Sonatas, ConcertosBeethoven 106, Concertos 3-5Ravel Gaspard de la Nuit, Mirrors (sic )Rachmaninoff Piano Concertos, Etudes-Tableau (sic )Liszt Sonatas (sic ), Etudes, Hungarian Rhapsody 15, ConcertosProkofiev Sonatas 7 and 8, Concertos 2 and 3Stravinsky PetrushkaBrahms Concertos
A lot of obscure 20th- century stuff by composers like Glass, Hamelin, and Ives.
Welcome to Pianostreet. Don't forget Sorabji's Opus Clavicembalisticum. OP, as I'm sure you know - assuming that you actually play such pieces - that all of these pieces are at the very height of difficulty and constitute what are maybe the worst possible suggestions imaginable within 'standard repertoire.' Being a pianist who is playing Chopin/Rachmaninov Etudes, you must yourself know this, and surely your teacher is assigning you works as are fit for you. Listen to your teacher. But you can try the Rach 33-9, there are just two or three truly 'transcendentally difficult' measures in the whole etude (you can either simplify them or practice your brains out), assuming you can play your scales and are willing to learn the figures in the LH (doesn't take a ton of time). Have you tried it?Ah yes, the 'obscure' Philip Glass, well-respected composer of piano music. I suppose it has been a while since I've seen an AMEX commercial with his music in it. And Hamelin! Who can forget his lecture series at the Darmstadt on composition: "More Octaves." Boulez and Stockhausen were rapt, another very serious 'composer' Presumably the Ives work that Beethovenfan01 has in mind is the nigh-unplayable Concord Sonata xDIMSLP has the Mathews series of progressive concert pieces free for download, btw. Maybe you can find something in there.
Yes of course that was all sarcasm, I hope that's clear ...In all seriousness, many of Chopin's Nocturnes and many of Beethoven's sonatas are very good to have in your repertoire, as are Schubert's Impromptus, the Liszt Hungarian Rhapsody No. 2 (or 6), the Debussy Arabesques, and the Brahms Rhapsodies Op. 79.fftransform, a little more appropriate for the OP's level, I think? That other list was obnoxious on purpose.