A four-armed robot can now improvise music as well as human bandmates

He bobbed his head with the groove, and leaned way in when he wanted to play more complicated melodies, rocking and rolling with the beat of the jam. This wasn't a your average jazz band member, though--this was Shimon, a four-armed robot marimba player built by the Georgia Institute of Technology to be able to listen to music, improvise, and play along with human musicians. At a performance at Moogfest, a four-day music and technology festival in Durham, North Carolina, Gil Weinberg, the lead researcher at Georgia Tech's Center for Music Technology, demonstrated what he and his lab have been working on for the past 12 years. Their efforts have aimed at augmenting the creative capabilities of humans with robotics. That can mean robots like Shimon, which uses machine-learning programs trained on music theory and a wide range of musical styles, from chamber music to dubstep, to be able to add a superhuman element to musical performances, playing chord structures that would be physically impossible for humans to hit. But it can also mean robotic enhancements for humans: At the concert, Weinberg introduced Jason Barnes, a drummer who lost the lower part of his right arm a few years ago.