sorabji - opus clavicembalisticumligeti - etudessatie - vexationscage - 4'33nancarrow - tango?
It's "potato" I'd say Bach WTCBeethoven sonatasChopin etudes
Personally, I would like to see Bertini studies, Schubert moment musicaux, Scriabin preludes and Janacek 'On an overgrown path' on any list. I'll pass on the Ligeti, Cage and Messiaen.
sorabji - opus clavicembalisticumligeti - etudes(...)
Very good music for people who are not beginners can be found by Heller, Kirchner and Reinecke, all disciples of Schumann. Cycles of pieces like Chopin's Preludes are really full of rather frightening stuff I'm afraid.
Baroque :JS Bach - Selected pieces from Anna Magdalena Buchlein30 Inventions/sinfonias Selected P's and F'sScarlatti - Selected SonatasClassical : Clementi - Selected Sonatinas (?)Hadyn - Selected SonatasLiszt - Selected piecesMozart - Selected SonatasRomanticBeethoven - Selected piecesChopin - Selected PreludesSelected piecesSchumann - Kinderscenen - Selections fromAlbum for the Young - Selections ? ImpressionisticDebussy - Children's corner - Selected piecesRavel - Selected pieces20th C.Bartok - selected piecesShostakovich - selected piecesOkay, I can think about reasons for all of these but I won't write them in just yet.