Musicological Observations 8: Essential listening from post-1945 New Music?

I was considering what I thought should be essential listening from the repertoire of post-1945 new music, to which anyone doing a music degree course which has a Western art music focus should be exposed during the course of their study. I want to be uncompromising and avoid easy populist, ‘democratic’, patronising choices (but look to major, difficult works for which exposure and explication at a university level might really make a difference. So here are six suggestions – I am looking for some others (I have lots of ideas, naturally, but am interested in those of others) that might make this up to ten suggestions. Please do post below. I am aware that there all the below choices are men, so would welcome various views on which works of women composers might also be included, according to the criteria I lay out.

Pierre Boulez, Pli selon pli (1957-62, rev. 1989-90)

Karlheinz Stockhausen, Kontakte (1958-60)

Luigi Nono, La fabbrica illuminata (1964)

Morton Feldman, Violin and Orchestra (1979) (only an excerpt is included above)

Brian Ferneyhough, Second String Quartet (1980)

Helmut Lachenmann, Allegro sostenuto (1987-88, rev. 1989-91).