Interestingly, Smule's first product wasn't musical. It was Sonic Lighter, a virtual lighter.
"We thought it would be fun," says Smith, who is still enrolled at Stanford. "There were a lot of lighters, but none gave you the true physical experience of the lighter and let you blow out the flame."
Smule has sold 300,000 copies of the 99-cent lighter program. It followed up with a virtual firecracker (Sonic Boom) then Sonic Vox, which lets you alter your voice to sound like Darth Vader or high-pitched babies. Both sold around 150,000 copies.
Then came the Ocarina, named after an ancient Chinese flute-like instrument with four holes for notes. Its inspiration was an old Nintendo video game, The Legend of Zelda.
Wang remembered that one of the characters in the game carried around an ocarina. "Depending upon the melody the character played, it would transport you to a different time," Wang says.
The iPhone community got it, in a big way.
"Within four days of its release, it became the No. 1 best-selling app on the store," recalls Wang. "People were learning how to play music for the first time, on an iPhone."
Ocarina is currently the No. 1 best seller in the music category.
For the Leaf Trombone, Wang says, he wanted to create a "whimsical, wacky" instrument, like trying to make music from blowing on a leaf of grass.
"A trombone slide just made sense."
Making music on a laptop
Wang was born in China, where he lived with his grandparents before moving to Atlanta at age 9 to join his parents. His father now teaches statistics at a New Jersey college.
Wang studied computer science at Duke, figuring he'd be a video game designer. He worked in the software industry in Washington, D.C., before heading to Princeton for his master's and Ph.D. in computer music.
"It seemed like a powerful building block for everything I loved doing," he says. "It has music and graphics and networking — everything I loved about video games."
At Princeton, Wang and his adviser, Perry Cook, co-developed ChucK, the software Wang uses to make music on iPhones and laptops. The language is used at many universities, including CalArts, Georgia Tech, Princeton and Stanford, Wang says.
In 2007, he got the "dream job" of assistant professor at Stanford's CCRMA (Center for Computer Research in Music and Acoustics). Within a few months, he had organized the Stanford Laptop Orchestra and laid the bricks for the Stanford Mobile Phone Orchestra. Then Smith came to him with the idea for Smule.
"I was hardly sleeping at all, because so much was going on, but I had to do it, because it seemed like such an awesome research opportunity," Wang says. "It can bring the vision of computer music to a much wider audience."
Stanford has a long history of seeing outside projects developed by its researchers (think Google and Hewlett-Packard), and the university has a dedicated office in place to help.
"Ge is very cognizant about keeping Smule separate and not using Stanford resources for Smule," says Steve Sano, head of Stanford's music department. "He's attentive to what the boundaries are."
Smule has 12 employees working out of a facility in nearby Menlo Park, most of them Stanford students.
Smith, a former Silicon Valley entrepreneur who brought a company public (the now defunct Tumbleweed), then quit to focus on music, serves as CEO to Wang's chief technology officer.