Hydraulis (hydraulophone, whater organ )

I thought it's one of the newest instrument, but it was invented in ancient Greece. I'm impressed.

Some information from Wikipedia:

The water organ is a type of pipe organ blown by air, where the power source pushing the air is derived by water from a natural source (e.g. by a waterfall) or by a manual pump. Consequently, the water organ lacks a bellows, blower, or compressor.

On the water organ, since the 15th century, the water is also used as a source of power to drive a mechanism similar to that of the Barrel organ, which has a pinned barrel that contains a specific song to be played. The hydraulis in ancient Greek is often imagined as an automatic organ, but there is no source evidence for it. One of the oldest automatic instruments known is the automatic flute player invented by Banū Mūsā brothers in 9th century Arabia.

A hydraulis is an early type of pipe organ that operated by converting the dynamic energy of water into air pressure to drive the pipes. It is attributed to the Hellenistic scientist Ctesibius of Alexandria, an engineer of the 3rd century BC. The hydraulis was the world's first keyboard instrument and was, in fact, the predecessor of the modern church organ. Unlike the instrument of the Renaissance period, which is the main subject of the article on the pipe organ, the ancient hydraulis was played by hand, not automatically by the water-flow; the keys were balanced and could be played with a light touch.

How it looks:




Example of playing: