There are a few comments here complaining about the intellectual nature of Carter's music, saying it doesn't speak to the heart. All I can say is this: if you listen to just the beginning of his Concerto for Orchestra and don't feel some wonderment at the hushed percussion giving away to the tremelo strings and other instruments joining in, and not see this is the beginning of some epic journey, that is it the oppisite of a mere formal exercise, then you're either willfully not paying attention or you're simply dead inside.Yes, Carter placed strict formal demands on himself-so did Bach, perhaps even more so. If I may be very old fashioned, I have to say the greats are the ones who speak directly while putting the greatest strictures on themselves: they find the form to suit their emotions.