If you're a drummer or fan of drumming in general, you've probably checked out Drum Channel. They've created what I'd have to assume is any drummer's dream. They have a whole library of videos featuring a who's who of legendary drumming talent getting together for some talk and some jamming.
Terry Bozzio, in case you didn't know, is probably best known in Prog circles as the Zappa drummer tasked with mastering The Black Page. There's little doubt that Mike Portnoy would list Bozzio amongst his influences.
This video, (almsot two hours long!) features some drumming duals between the two legends and some very interesting conversation. They quiz each other on their history and influence and aren't afraid to talk about the math behind the complex drumming that is their trademarks. The mood is casual and the dialog is candid. If you are even moderately interested in either of these progressive drumming icons then you should probably set aside some time and check this out.
Mike Portnoy (Dream Theater) with Host Terry Bozzio Rebroadcast of DC LIVE