John Adams's response to 9/11, On the Transmigration of Souls is a bit under a half hour in length, but seems timeless. Partly this is the lack of narrative, partly Adams' shimmering music.
Adams keeps things down to earth. There's an underlay of taped sounds: traffic and street noises, and a reading of names of victims. The texts sung are taken from the homemade posters for the missing that appeared on walls and lampposts in New York City in the wake of the World Trade Center disaster. The first word heard is "missing"; the first sung word is "remember." Short phrases, even single words, commonplace in themselves, are woven into a dignified, emotionally moving tapestry. The effect is often meditative, but the element of conflict inherent in the acts of violence that took the lives of those whose names are being heard, and about whom the choruses are singing, is depicted by dissonances in the orchestra, clanging bells, and recorded sirens just before the emotional climax at the screaming anguish of the words "I wanted to dig him out, I know just where he is." After that, dissonance gives way to darkly lyrical music that's more soothing, sympathetic without pretending to have solved anything.