People have long joked about needing a third arm to tackle tasks in a timely manner, and researchers at the Georgia Institute of Technology recently created one.

People have long joked about needing a third arm to tackle tasks in a timely manner, and researchers at the Georgia Institute of Technology recently created one.
The robotic appendage was built with drummers in mind. 
Measuring about 2 feet long, the mechanism listens to the music and determines the appropriate tempo.
Which cymbal or drum it plays is informed by the wearer’s actions. 
An accelerometer gauges distance from the desired instrument surface and detects where the drummer’s arms are at any given moment.
The team is now looking into ways of