By Danya Henninger.

If you see a pack of teenagers singing, hooting, howling and shouting as they march down Germantown Avenue this weekend, don’t be alarmed. They’re doing it for democracy.

Saturday’s traipse down the cross-city corridor will be led by MIT Media Lab music professor and inventor Tod Machover. It’s one of several meetups Machover has planned when he returns to Philly (see details below) for another swipe through its aural fabric to collect sounds for his latest undertaking: a semi-crowdsourced symphony called “Philadelphia Voices.” The symphony will be performed by the Philadelphia Orchestra next spring.

That’s right, come April 2018, the illustrious Kimmel Center stage will be filled with shouts and screams and yowls and yips from the street.

How’d Machover convince orchestra bigwigs to let this happen? Well, he has quite the reputation. He’s mounted similar projects in various cities around the world — Toronto, Lucerne, Detroit, Perth — turning each one’s urban cacophony into a unique overarching symphony. All have been hailed as successes.

By Catherine Curro Caruso.

The exhibit, one of the few with a sound component, represents the City Symphony projects headed by Professor Tod Machover at the MIT Media Lab. In each City Symphony, technologies developed by Machover and his Opera of the Future Group allow anyone to contribute audio, video, original compositions using Hyperscore software, voices, and more, and to help shape the feel and story of each “symphony” through a new kind of collective creativity.