The futuristic online glasses known as Google Glass will add music functions over the next two weeks for the few thousand “Explorers” beta-testing the devices around the world. These include hands-free access to Google Play, the company’s streaming-and-downloading music service, a Shazam-like app that identifies unknown songs and stereo earbuds. “I may be in a lot of places and I hear things — I can search without having to pull out my phone or find an app,” says Young Guru, the longtime Jay Z mixer and DJ who has been testing the glasses for three months. “It allows me to do that so quickly.”

Some tech writers have likened Google Glass to Apple’s Newton — an impressive device that’s expensive ($1,500), ahead of its time and lacking practical applications. But Guru suggests music may be the killer app that justifies the operation. He made a two-minute video documenting a recent walk around Los Angeles, identifying a song at a Mexican restaurant, digging it up at a nearby record store, then scratching it in his studio.

“When the iPhone launched in 2007, it had a dozen apps on it and that was it. The whole app ecosystem didn’t exist until people could invent for the iPhone,” says Ed Sanders, Google Glass’ director of marketing. “That’s kind of where we are with Glass. Music is a big part of that.”

Beyond the functionality involving Play and earbuds, Young Guru foresees a time when Google Glass changes the way musicians think about performing and creating. He has used the glasses to replay the events of an entire day, zooming in on various “sounds of the city” and incorporating those rhythms into his music. And he has used them for long-distance collaborations. “I’ve done a couple things with a couple of my guys in Europe. I can actually see the fingering on a guitar player — ‘why don’t you move that to a half-step up?'” he says. “It’s the closest thing we can have to being in the same room. To be hands-free to scratch on a turntable or play percussion allows me to do so much more.”