Atlanta, Georgia (CNN) -- The ad might read, "Percussionist wanted, preferably marimba player, for jazz-influenced band. Must be able to improvise, bob head and wear metal."
And the perfect candidate? It may be Shimon, a marimba-playing robot that, despite having four arms, is remarkably human. It has a shiny aluminum-steel head that bobs with the music and acknowledges other people when they're nearby.
Like any jazz impresario, Shimon can listen to music, analyze its structure and improvise with other musicians. But instead of lifelong musical training, Shimon relies on complex algorithms to identify tempo, beats, chord progressions and melodic dissonance and consonance.
"We interact with this [robot] very differently [than with humans]," said Ryan Nikolaidis, a PhD student at the Georgia Tech Center for Music Technology. Nikolaidis programs Shimon, whose name means "one who hears" or "one who is heard" in Hebrew.
"Having the presence, having a head that bobs. ... It looks at you when you're soloing and looks at itself or looks at the other players. It's really a different level of social interaction," he said.
John Coltrane. Thelonious Monk. Shimon can improvise like the best of them. The robot morphs the styles of these jazz masters to produce novel, surprising arrangements that both inspire and challenge Shimon's human bandmates.
"We're interested in improvising like a human but playing like a machine," said Nikolaidis, who also performs with the robot on his piano keyboard in a constant feedback loop of teach and learn.
"Being able to shift between different influences and create a rich vocabulary that's nothing like any human would ever play ... hopefully this then inspires us to play differently as well, play something that we wouldn't play with other humans," he said.
Gil Weinberg, director of the Georgia Tech Center for Music Technology, built Shimon two years ago with help from his colleague Guy Hoffman and Roberto Aimi of Alium Labs. The National Science Foundation helped fund the project.
Shimon isn't Weinberg's first foray in making robotic maestros. He and his students developed Haile, a robot drummer, in 2006. Like Shimon, Haile learns, performs and improvises alongside flesh-and-blood musicians.
Weinberg also helped pioneer the popular iPhone app ZOOZbeat, which helps anyone -- regardless of musical talent -- create songs by waving and shaking their phones.
In December, a group of musicians in Japan used the app to jam remotely with Shimon as it played at Georgia Tech. The performance was billed as the first intercontinental musical interaction between humans and robots.