This is a great list! For anyone who's interested in a few more recommendations: * For my money, John Adams's best composition this century is El Niño (https:

This is a great list! For anyone who's interested in a few more recommendations: * For my money, John Adams's best composition this century is El Niño (https://www.youtube.com/watch?v=a2IUdBLVkOQ https://www.youtube.com/watch?v=a2IUdBLVkOQ), though Doctor Atomic is also amazing (https://www.youtube.com/watch?v=AlUHKHLk_VU https://www.youtube.com/watch?v=AlUHKHLk_VU). The former is a nativity oratorio and the latter is an opera about Oppenheimer and the Manhatten Project. On the Transmigration of Souls (a 9/11 memorial piece) is also especially moving. (https://www.youtube.com/watch?v=bwoasXzLdVY https://www.youtube.com/watch?v=bwoasXzLdVY) * Revelation, by Michael Harrison. This piece uses just intonation rather than the more common equal temperament. In just intonation, the notes are tuned so that the fifth is "pure" --- i.e., the frequencies are in an exact 2:1 ratio. This causes the other intervals to sound slightly out of tune and gives the music a really otherworldly feel. https://www.youtube.com/watch?v=D4oKzSRs3sA https://www.youtube.com/watch?v=D4oKzSRs3sA (Michael Harrison, incidentally was a student of La Monte Young who revived just intonation and composed a 5-hour piano piece called The Well Tuned Piano. https://www.youtube.com/watch?v=sfWV4rNB6KE https://www.youtube.com/watch?v=sfWV4rNB6KE) * Sleep, by Eric Whitacre. Now a classic choral composition. (Cloudburst is also great, but was composed in 1995 at the age of 21!) https://www.youtube.com/watch?v=Yw5gupbe9E0 https://www.youtube.com/watch?v=Yw5gupbe9E0 * Orient & Occident by Arvo Pärt. Pärt has a lot of great works like Für Alina (which marked his departure from serialism), but most of them were composed in the 20th century, although he's still active! https://www.youtube.com/watch?v=xGMaIfNdqH8 https://www.youtube.com/watch?v=xGMaIfNdqH8 * "...similarities between diverse things", by Joby Talbot (2002). For piano trio and vibraphone. The title comes from a mathematician friend of Talbot's who died at the age of 20 and used that phrase to describe why he found mathematics beautiful. https://www.youtube.com/watch?v=4tawlg0RN4I https://www.youtube.com/watch?v=4tawlg0RN4I * The Veil of the Temple, by John Taverner. A magisterial work lasting 7 hours. https://www.youtube.com/watch?v=62pRsgwSYjs&list=PLga2eRXhIyUgJmsqGzAaE19EPGz_C1kSn https://www.youtube.com/watch?v=62pRsgwSYjs&list=PLga2eRXhIy... * Chanson Eloignee, by Morten Lauridsen. A lot of Lauridsen's more famous works were composed in the late 20th century, but he is still active. https://www.youtube.com/watch?v=4Ajmn9m-C9Y https://www.youtube.com/watch?v=4Ajmn9m-C9Y And there's a lot more that I'm missing. A couple of other favorites of mine that missed the 21st century by a few years: * Concerto for Harpsichord and Strings by Michael Nyman (1994) https://www.youtube.com/watch?v=Svf9yuouXww https://www.youtube.com/watch?v=Svf9yuouXww * Danzón No. 2 by Arturo Marquez (1994). This piece is great fun and helped to bring Gustav Dudamel to fame after he conducted it with the Venezuelan Youth Orchestra on their world tour in 2007. (Dudamel is now the conductor of the LA Philharmonic.) https://www.youtube.com/watch?v=ZXeWiixwEz4 https://www.youtube.com/watch?v=ZXeWiixwEz4 * 24 Preludes for Piano by Lera Auerbach https://www.youtube.com/watch?v=G9u5wc2CkL8 https://www.youtube.com/watch?v=G9u5wc2CkL8 Lots of great music out there!