Merry Christmas from the flying robots of Switzerland. Watch as a Swiss quadrocopter named “Echo” plays a little something for the holidays.

The robot is a test subject at the Swiss Federal Institute of Technology’s Institute for Dynamic Systems and Control. Researchers put a piano in their Flying Machine Arena so Echo could play “Jingle Bells.”

Researchers study high-performance flight, fast-changing flight maneuvers and other topics using the quadrocopters. The piano isn’t a new notion — one of the lab’s researchers, Angela Schöllig, spends her time synchronizing quadrocopters’ flight to music.

Watch to the end and you’ll see this wasn’t easy to do.