The 5th Barcelona Music Hack Day took place last week, part of the Sónar+D music and technology festival. The event was well attened by people from all over the world and well documented- photos were taken by festival representatives as well as a number festival goers who were able to observe the hackers hard at work during festival hours.
And what a sight all the hacks in progress were! A lot of hardware was used to produce a number of sounds, songs, noises, and performances never before expereienced. Legos, Patchblocks, Enobio brain sensors, an Oculus Rift, Xth Sense sensors, Estrella Damm beer cans, monomes, LED wired shoes, and more were worked into the projects.
In the mix of it all, there were still a couple hacks that used the Rdio APIs to great effect.
Collaborative playlist creation and democratic tracks ordering for use at parties, playing music from Rdio. Winner, best use of Rdio API
webmlr - Site, GitHub
A web monome to control and play audio samples from the server, your local machine or a track from Rdio. Also handles a real monome device input & output.
It helped that the Music Technology Group was right next door- a number of students attended, bringing a lot of deep technical knowledge of sound and music.
A list of all of the hacks is up at Hacker League.