Some tech notes from a pro-audio software developer:
- All the samples are OGG ( http://chrome-jam-static.commondatastorage.googleapis.com/xm... )
- They're using some "DMAF" engine for the audio, though I can't figure out who made it: http://www.jamwithchrome.com/js/compiled/dmaf_all.js
It's pretty serious stuff from the looks of it - It's got a node graph with different DSP modules (envelope follower, delay, ADSR, distortion, LFO, chorus, compressor, phaser, equalizer, biquad filters), it plays MIDI files, and more.
It's all written in JavaScript too, and there's no way you'd write this just for one Chrome experiment. I don't see any outside party acknowledged on the website, but I'd guess that this DMAF JS audio engine is licensed from someone.
It's interesting to see what they've been able to do with the Web Audio API and JavaScript, but I think the Web Audio API is going to be forever limited to toys like this unfortunately. You just can't do real-time audio with a garbage collector waiting to pounce.
I developed a similar application for Chrome (which coincidentally had the codename "Jam"), but instead, it uses Native Client for audio instead of the Web Audio API. It's called SongStarter, and you can jam with it here: https://chrome.google.com/webstore/detail/jbkilbgofafobojkif...
(NaCl apps must be installed from the Chrome Web Store for the time being, otherwise they won't work. Google's choice...)