Hej!
What program do you use to make it show up as a midi controll in the software synth? I'm hoping midiox will work for me, it free+donation.
Is max/msp the thing if i'd want to become a midi to softwaresynth master?
And also. I'm really really a beginner in programming. Would it be possible to see the code for this. Eventhough there are instructions on in the playground about how to use the 4051, i don't understand how to make each leg of the multiplexer respond to a specific midi note.
Also nice to see that it's polyfonic 
and you played it well!!!