Peter Lieberson has died, he was only 64. Times obit here, one of his students writes here, NPR archive here. Sequenza 21, with video, here. I never met the gentleman, but I coached his beautiful Rilke Songs at Songfest a few years ago. Lorraine Hunt Lieberson sings excerpts here.
Update: a must-read essay by Lieberson here. (Thanks to Do the Math) A reminiscence by Ross Bauer here.