MIDI.js: Playing Audio in the Browser with Javascript

“Everything old is new again.”

        –Peter Allen

The evolution of the web browser is in many ways the repackaging and reintroduction of technologies that have existed on the desktop for decades. Consider WebGL replacing OpenGL with the help of the <canvas> tag and HTML5 video replacing ActionScript/Flash with the <video> element.

At the well-run Science Hack Day SF I was able to dive into these new browser technologies along with Jade and Rich to build Symphony of Satellites, an app that generates music based on the trajectories of satellites currently overhead. Using data calculated live from NORAD, musical notes ride and set as satellites appear and disappear over the horizon. The velocity of the satellite, its elevation, and other aspects of its trajectory determine the instrument, pitch, and rhythm of notes generated by that satellite and the visualization on the page. The promo video for the app is worth watching.