Sure, every band geek has heard of the mythic contrabass sax. But I bet you didn't know there were contrabass clarinets and french horns or subcontrabass recorders, flutes, and... uh... this thing. On the other end of the spectrum you've got the sopranino recorder, saxaphone, clarinet, and ukulele.
An entertaining history of ClariNet, which its founder Brad Templeton describes as the first dot.com. Lots of good reading linked on that first page.
Two flutes at once. Two guitars at once. (Honorable mentions.) Two recorders at once, 100% nose-powered. Two trumpets at once (breakdown at three).Two harps at once. Two saxophones at once. (Bonus: Clarinet/sax unos.) [more inside]
Xaphoon! It's a saxophone! No, it's a clarinet! It's dirt cheap and it fits on your pocket! Apparently these have been around for twenty years, but I've never heard of them before. I've ordered myself one of the plastic ones. Has anyone here played one of these things?
clarinet databases - what has 2691 composers under 2725 names, 6564 titles under 6684 names, comprised of 7669 publications and representing 8022 sets of instrumentation? the clarinet composition database. the site also features a searchable discography of important clarinet recordings.