Update: I won an Echonest Prize for the Echonest Midi Player!
The main goal of Music Hack Day is to explore and build the next generation of music applications. It's a full weekend of hacking in which participants will conceptualize, create and present their projects. Music + software + hardware + art + the web. Anything goes as long as it's music related.
I'm participating in the Musichackday Stockholm! I will try to have some hardware talk to web-services.