Hydraulic organ from the 3rd century BC

[snyders]

A hydraulis is an early type of pipe organ that operated by converting the dynamic energy of water (Ancient Greek: ὕδωρ hýdōr) into air pressure to drive the pipes (Ancient Greek: αυλός aulos). Hence its name hydraulis, literally "water (driven) pipe (instrument)." It is attributed to the Hellenistic scientist Ctesibius of Alexandria, an engineer of the 3rd century BC.

http://en.wikipedia.org/wiki/Hydraulis