Hydraulis

The earliest keyboard musical instrument

Hydraulis is an ancient Greek mechanical aerophone producing a strong high-pitched sound. Constructed in Alexandria, it was used in horse races and military music performances.

Hydraulis, the so-called water organ, was invented in the 3rd century BC by the engineer Ctesibius of Alexandria. Its functioning and mode of use are described by the scientist Hero (Heron) of Alexandria and the engineer Marcus Vitruvius Pollio.