We'll make it compatible with both MIDI controllers as well as your laptop keyboard. We were initially using the YouTube API for samples, but the latency issue was too large and responsiveness of the keys were one of our top priorities (especially when doing something like drumming). Having entire audio clips buffered client-side made for a much happier hackathon. We'll look into how we can better control buffering YouTube audio data so that people can sample from there as well. So YouTube is a maybe for now depending on if we can make playback responsive enough. Regardless, We'll do a ShowHN as soon as people are able to start playing with any form of the sequencer.
What I really want to see is Cloud Sequencer making it really easy for anyone to try their hand at sampling and mixing audio without expensive equipment and software. Unlike other members of the team, I hadn't done much audio work before the hackathon but I'm hooked now. It was a lot of fun. Thanks to PennApps and everyone who stopped by to play some awesome music with us.