The arm has been developed to know where the various parts of your kit are and adapt to your playing style - great for those without a sense of timing (wouldn’t want to be shown up by your own metronome, would you?) The arm can improvise all by itself and can even do call and response.
An EEG headband is also in development that Weinberg hopes will identify patterns that would allow the arm to react when the musician thinks about changing tempo.
The eventual goal is to have the third arm helping technicians with repairs and experiments or to assist surgeons in theatre by passing them tools or even participating in surgery. Weinberg said that drumming was the perfect place to start though as music is based on timely, precise movements. Presumably it’s also because no one is going to be hurt. Except the audience.
The potential benefit to mankind may be worthy, but giving drummers a third arm? Wasn’t that what drum machines were invented to avoid? Or perhaps this is the start of replacing drummers with robots altogether? Now there’s a thought.
