@InfraBlue,
(It's strange to me that the thread is about non-symphonic works and half the stuff that's been named have still been symphonic, but I guess you mean "non-symphonies.")
In the symphonic non-symphonies category, here are some of my favorites:
Poulenc: Organ Concerto
Bernstein: Symphonic Dances from
West Side Story
Bartok:
Music for Strings, Percussion, and Celeste
Ravel:
Mother Goose Suite
Stravinsky:
Petrushka
Britten:
Serenade for Tenor, French Horn, and Strings
Debussy:
La Mer
In the non-symphonic non-symphonies category, some more favorites:
Ravel:
Le Tombeau de Couperin
Ligeti: Piano Etudes (especially Book 2)
Poulenc: Sextet
Bach:
Art of Fugue
Stravinsky:
Agon
Beethoven: Piano Sonata No. 30 in E
Debussy: Sonata for Flute, Viola, and Harp
Boulez:
Le Marteau sans Maître
p.s. I didn't mean for this post to be a response only to Infrablue's post. I hit the wrong "reply" button. Still learning my way around the new layout!