But what's probably more interesting to SoundCloud users is a new Instagram-compatible Web app called Story Wheel that the Berlin company launched Monday.
"It's a really big thing for us to have the community get to that point," Alex Ljung, SoundCloud's co-founder and chief executive, said in an interview. "It's just been a great last year for us. Everything has sort of ramped up faster and faster and recently we're signing up about a million users a month."
The audio-hosting and -streaming service, which we've said aspires to be the YouTube of audio, has grown largely by word of mouth, Ljung said.
"The SoundCloud community is really pushing it forward," he said. "We see now super clearly that sound is mobile with the number of sign-ups and usage growth on the mobile app side. We've also seen over the last year just how wide sound can be beyond music."
One example of that diversity is that there are more than 3.3 million tags that SoundCloud users identify their recordings with, Ljung said.
Another example of SoundCloud's "sound is more than music" ethos is the Story Wheel app, which is essentially an online version of a slide show with a projector sound effects, to re-create the feeling of sharing photos the old-school way with friends and family.
On Monday, Ljung and SoundCloud co-founder and Chief Technology Officer Eric Wahlforss posted a Story Wheel of their own that offered up a bit of company history: Their first SoundCloud "office" was a Berlin coffee shop.
The app started last November in Boston as a project at Music Hack Day, which SoundCloud helps organize, then continued in the company's Berlin and San Francisco offices. The inspiration for Story Wheel came when SoundCloud engineers found themselves telling each other the stories behind the photos they posted to Instagram.
"We chose Instagram is because it's the service we use the most for our own photos," Ljung said. "We built Story Wheel because it's something we wanted to see and we thought it was something our users would like to see and use too. And we built the whole thing on the same API that we offer to our developers, who have made more than 10,000 apps on our platform."
About a year ago SoundCloud had about 2 million users, Ljung said, adding that he thinks third-party developers and the popularity of the company's mobile apps deserve as much credit for the growth to 10 million users as the word of mouth spread by users.
So where does SoundCloud go from here? Ljung said the 80-employee company is focused on continuing its growth and creating more things like Story Wheel that show users what they can do with the audio files they record and share on SoundCloud's website.
Aiding that effort is a recent round of venture funding and the addition of Mary Meeker, a renowned tech analyst and partner at the investment firm Kleiner Perkins Caufield & Byers, to SoundCloud's board as an observer.
Ljung, however, wasn't too interested in talking about Meeker or just how much money SoundCloud has raised.
"I think for us it's not such a big deal," he said. "It's just kind of like a background thing that helps the company grow. It's great to have good partners and have great apps built on our platform. But for us, the 10-million-user figure is really more interesting. Everything we do, we think about how it will affect our users because without the users, none of the other stuff is there."
-- Nathan Olivarez-Giles
Image: A screen shot of SoundCloud's Story Wheel Web app. Credit: SoundCloud