A hydraulist is a musician who plays a hydraulic instrument, such as a water organ

Water organ

The water organ or hydraulic 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 or by a manual pump...

 or a hydraulophone

Hydraulophone

A hydraulophone is a tonal acoustic musical instrument played by direct physical contact with water where sound is generated or affected hydraulically. Typically sound is produced by the same hydraulic fluid in contact with the player's fingers...

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Whereas hydraulists in Roman times pressed keys to open air valves to allow a water-powered wind source to blow air into wind pipes, modern hydraulists make sound with water, using a new instrument called a hydraulophone

Hydraulophone

A hydraulophone is a tonal acoustic musical instrument played by direct physical contact with water where sound is generated or affected hydraulically. Typically sound is produced by the same hydraulic fluid in contact with the player's fingers...

At the International Computer Music Conference

International Computer Music Conference

The International Computer Music Conference is a yearly international conference for computer music researchers and composers. It is the annual conference of the International Computer Music Association ....

 sounds from acoustic hydraulophones were picked up using hydrophone

Hydrophone

A hydrophone is a microphone designed to be used underwater for recording or listening to underwater sound. Most hydrophones are based on a piezoelectric transducer that generates electricity when subjected to a pressure change...

s (underwater microphones) and fed through computer systems to create new musical textures for an underwater hydraulophone concert.

Notable hydraulists

• Nero, Emperor of Rome, was a hydraulist, playing on the hydraulis, a pipe organ in which the power source for the wind (air) blown into the pipes, comes from a standpipe full of water.

• Ryan Janzen is a modern-day composer for hydraulophone. Works include Suite for Hydraulophone, and various orchestral compositions for hydraulophone. Janzen was a hydraulist at Nuit Blanche, the all night arts festival.