Crowdsourced piano-playing lets you choose the tune

Tae Kim steps back from the piano and shakes his hands limply. "If I ever do this again, I'm going to have to remember to take a break," he says.

Kim, a graduate of the New England Conservatory, had been playing the piano in the MIT Media Lab's "Opera of the Future" lab for three and a half hours at the lab's spring meeting earlier this week. But there was no sheet music on the music stand. Instead, Kim watched colourful bubbles on an iPad that displayed what people watching along online wanted to hear.

The piece was "an experiment in collaborative improvisation", says composer and lab directorTod Machover. People at home could listen to ten clips of music from Bach to the Beatles andrate their preferences. If listeners said, "This is nice, but I'd like a little more Radiohead and a little less Schubert," Kim had to respond by improvising in real time.

"There's something about improvisation that I find really enjoyable," Kim told New Scientist."There's a freedom that you don't get otherwise. But it's difficult, because I always have to think ahead." He said he had to learn a few Radiohead songs just that morning, and sometimes found himself just playing the melody to "Yellow Submarine" over and over again.

"If I had a say in it, I'd have put in more Chopin," he admitted.

The experiment was a sort of dry run for a project Machover is working on called "A Toronto Symphony: Concerto for Composer and City" scheduled to premier 9 March, 2013. Machover wants the entire city of Toronto, Canada, to participate in the symphony in a feedback loop. He calls it "the next step beyond crowdsourcing".

"Could you really make a collaboration between a lot of people so that as an artist, you're satisfied, and the audience is satisfied?" he asked. The collaborative improv Kim demonstrated on Tuesday might make a good platform.