Alex Ross points out that Q2, the New York classical streaming station, has the recent Varèse concert online. And impressively, the streams are in both the form of the entire concert with commentary as well as the individual works, which are embeddable:
Density 21.5
Un Grand Sommeil Noir
Amériques, arranged for 8-hand piano
Poème Électronique ringtone
Wikipedia:
Allmusic's Sean Hickey says, "According to the composer, Density 21.5 is based on two melodic ideas — one modal, one atonal — and all of the subsequent material is generated from these two themes. Despite the inherent limitations of writing for an unaccompanied melodic instrument, Varèse expertly explores new areas of space and time, utilizing registral contrasts to effect polyphonic continuity."
On the other hand, I can't for some reason subscribe to
the Q2 blog in Google Reader: