h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Another interesting instrument is the aulochrome; like the ancient aulos but capable of all the notes in an octave. It is in fact two (improved) soprano saxophones stuck together side by side (but capable of independant playing). It was invented by a Belgian guy called Francois Louis around 2000. He is currently looking for a manufacturer

Sounds interesting! In what way is it better than a normal soprano saxophone?

He's made it lighter, combined they're only 10g more than a normal soprano. He's also done some more techy-stuff, like make keys easy to remove and fiddle with some mechanisms, the keys are split in two, one for each, so it is possible to play any two different notes. This gives some interesting effects like tunable beats from deviations in pitch, and some other effects I don't understand, I'd recommend looking it up.