Hydraulophone

Infobox Instrument
name=Hydraulophone
names=Woodwater instrument

---

classification=
*Water
*Woodwater
*Reedless
*Single-reed
*Double-reed
range=Basic range of a diatonic hydraulophone with 12 water jets:
More detailed ranges and compasses appear below.
related=
*Flute
*Glass harmonica
*Pipe organ
musicians=
*Hydraulists
articles=

The term hydraulophone refers to one of:
*an interactive acoustic sound sculpture, typically in the form of a civic centerpiece used in landscape architectureFluid Melodies, in WaterShapes, Volume 10, Number 2, Pp36-44, New York, NY, USA] ; or
*a musical instrument that is played by direct physical contact with hydraulic fluid (typically water) in which sound is generated or affected hydraulicallyHydraulophone design considerations: absement, displacement, and velocity-sensitive music keyboard in which each key is a water jet, International Multimedia Conference archive, Proceedings of 14th annual ACM international conference on Multimedia, Pp 519-528, Santa Barbara, CA, USA] . Typically the sound is produced by the same hydraulic fluid that is in direct contact with the player's fingers [flUId Streams: Fountains that are keyboards with nozzle spray as keys..., Proceedings of ACM Multimedia 2005, Pp. 181-190, Singapore] ; or
*an acoustic sound-producing mechanism that is used as an interface or input device involving the monitoring of fluid flow. Examples include hydraulophones for fluid-flow monitoring and measurement applications, such as building automation, equipment monitoring, and the like (e.g. determining which faucet or toilet in a building is operating and how much water it is consuming)Arrays of water jets as user interfaces: Detection and estimation of flow by listening to turbulence signatures using hydrophones, by R. Janzen et al., Proceedings of the 15th International Conference on Multimedia, Pp. 505-508, Augsburg, Germany, 2007] .

Types of hydraulophones

This article concerns itself with hydraulophones that are musical instruments, or sound sculptures.There are various kinds of hydraulophones, some of which have reeds (one or more reed for each finger hole), and some which are reedless but still have one or more fipple mechanism or other sound-producing mechanism associated with each finger hole. Some hydraulophones include an underwater hydrophone pickup to allow the sounds produced by the water to be electrically amplified, whereas others do not use electric amplification. The use of electric amplification also allows various effects to be added, as with an electric guitar, as well as the possibility of making the hydraulophone function as a hyper-acoustic instrument (i.e. using computation to change the acoustic sound of the water into some other instrument)The Electric Hydraulophone: An acoustic hyperinstrument with feedback, International Computer Music Conference, Pp. 162, Copenhagen, Denmark] .

Relationship to woodwind instruments

The hydraulophone is similar to a woodwind instrument, but it runs on incompressible (or less compressible) fluid rather than compressible fluid. In this context hydraulophones are sometimes called "woodwater" instruments regardless of whether or not they are made of wood (as woodwind instruments are also often not made of wood).

Hydraulophone embouchure

Since humans do not breathe water, the water must be "blown" into the hydraulophone by way of a pump which can be hand-operated, wind operated, water powered, or electric (i.e. an electric pump). Unlike woodwind instruments in which there is one mouthpiece at the entrance to the flute chamber, hydraulophones have mouthpieces at every exit port from the chamber.

Whereas flutes have one fipple mechanism for the mouth of the player, along with several finger holes that share the one fipple mechanism, the hydraulophone has a separate mouth/mouthpiece for each finger hole. A typical park-hydraulophone for installation in public spaces has 12 mouths, whereas a concert hydraulophone typically has 45 mouths.

Embouchure is controlled by way of the instrument's mouths, not the player's mouth such that the player can sing-along with the hydraulophone (i.e. a player can sing and play the instrument at the same time). Moreover, the instrument provides the unique capability of polyphonic embouchure, where a player can dynamically "sculpt" each note by the shape and position of each finger inserted into each of the mouths. For example, the sound is different when fingering the center of a water jet than when fingering the water jet near the periphery of the circular mouth's opening.

12-jet diatonic hydraulophones

Many diatonic hydraulophones are built with 12 water jets, one for each of the 12 notes.The standard compass starts on A, extending up an octave and a half to E. We say 1 1/2 octaves in the sense that the high E has a frequency that is (2 * 1.5 = 3) times as large as that of the low A, ie. an octave (8va) plus a perfect fifth (P5) higher.

The standard A to E range, in which it is possible to play with polyphonic embouchure on any or all diatonic notes at the same time, is shown on the left side of the diagram. When playing only monophonically, some additional range is possible on certain hydraulophones, indicated here by small cue notes at the end-points.

Left, the extended notes come from closing key change valves or flexing key change levers, for sharpener, and flattener. To play a low G, one must be playing in C minor (with Ab) and close the flattener valve simultaneously. When playing on the high E jet, closing the sharpener valve produces an F.

With change-valves, the diatonic hydraulophone is polyphonic in the same sense as a so-called "chromatic harmonica" --- you can play chords and move all members of a chord down one semitone or up one semitone together, but the function of the valves is usually not separated to work on a per-note basis, so for example, you can play an A-minor chord, and flex the entire chord down to A-flat minor, but you can't easily play an A major chord without the use of polyphonic embouchure to bend only the middle note to a C# (which requires more skill than the average hydraulist has). Thus the "diatonic" hydraulophone is called "diatonic" conservatively to "under promise and over-deliver".

Finally, on the right, the additional extended range comes from the two octave-change valves (all notes can be shifted as many as two octaves down, or one octave up).

45-jet chromatic hydraulophones (concert hydraulophones)

Whereas park and pool hydraulophones are usually 12-jet diatonic, concert-hydraulophones are usually 45-jet chromatic.

45-jet hydraulophones have a 3 1/2 octave range of A to E, chromatic, plus an additional A-flat below the lowest A.The playing compass (45 water jets) is the same as the sounding range (45 notes).

Usually only 12-jet hydraulophones are installed in public spaces, but the rare exception is the 45-jet south hydraulophone at the Ontario Science Centre which is a concert-hydraulophone having this precise range/compass. It is available to any member of the public, for use, free of any admission fees or other cost, and it runs 24 hours a day.

Relationship to other musical instruments in the orchestra

The hydraulophone does not fit into any standard musical instrument classifications scheme that was in existence before the invention of the hydraulophone. In order to try to relate the Hydraulophone to other instruments, a physics-based organology has been introduced, subsequent to the invention of the hydraulophone. In this scheme, the top-level category of classification is the state-of-matter of that which initially produces the sound in the instrument.Natural Interfaces for Musical Expression: Physiphones and a physics-based organology, in Proceedings of the 2007 Conference on New Interfaces for Musical Expression (NIME07), Pages 118-123, New York, NY, USA]

The first three-categories of the Hornbostel Sachs system fall under the first category of the physical organology system, as they all produce sound from matter in its solid state.

This physical organology is as follows:
*1 Gaiaphones (Earth/Solid), instruments in which the initial sound-production medium is by matter in its solid-state, e.g. the piano.
**1.1 Chordophones: sound produced by solids that are essentially 1-dimensional (having a cross-section much smaller than their length, i.e. strings), e.g. violin, guitar, electric guitar, electric bass, etc.;
**1.2 Membranophones: sound produced by solids that are essentially 2-dimensional (much thinner than their surface area) membranes, e.g. drums;
**1.3 Idiophones: sound produced by bulk 3-dimensional solid matter, e.g. crystallophone, glass harmonica, xylophone, metallophone, etc., regardless of whether the instrument is operated underwater or in air;
*2 Hydraulophones (Water/Liquid): sound produced by matter in its liquid state; instrument itself may be played underwater or played in a surrounding medium of air, with water supplied only to the internal workings of the instrument:
**2.0 Waterflutes (reedless hydraulophones);
**2.1 Single-reed hydraulophones (typically having 1 reed for each finger hole);
**2.2 Double-reed hydraulophones (typically having 2 reeds for each finger hole);
**2.3 Polyreed hydraulophones (typically having 3 or more reeds for each finger hole);
*3 Aerophones (Air/Gas): sound produced by matter in its gaseous state, e.g. woodwind instruments and "brass" instruments;
*4 Plasmaphones/Ionophones (Fire/Plasma): sound produced by matter in a high-energy state such as plasma, e.g. plasmaphone, etc.;
*5 Quintephones (Quintessence/Idea): sound produced informatically, by electrical, optical, mechanical, or other computational/algorithmic means.Natural Interfaces for Musical Expression: Physiphones and a physics-based organology, in Proceedings of the 2007 Conference on New Interfaces for Musical Expression (NIME07), Pages 118-123, New York, NY, USA]

Classifications based on surrounding media

At the International Computer Music Conference in 2007, the conference theme was Immersed Music and featured some immersed performances and concerts. This raised some important questions regarding the role of the surrounding medium (air or water) in which a musical instrument is played, as well as the role of water in other non-hydraulophonic instruments.

For example, Benjamin Franklin's glass (h)armonica remains a friction idiophone regardless of the fact that it is played by wet fingers. A version of the armonica designed to be played underwater was recently created. This version is still a friction idiophone, not a hydraulophone.

Likewise, arrays of drinking glasses tuned with water are still idiophones, as the water is not what produces the initial sound, but is merely a tuning element.

Relationship between hydraulophone and the "strings, percussion, wind" taxonomy

Traditionally the orchestra is divided into three sections, strings, percussion, and wind. With strings and percussion instruments, the sound is produced by matter in its solid state, as for example, with a piano (which is both a string and a percussion instrument). With wind instruments sound is produced by matter in its gaseous state.

Hydraulophones add a new category of instruments in which sound is produced by water, unlike previously known instruments like the Glass harmonica and the Crystallophone which are idiophones that merely use the water to tune them or to enhance the friction. For example, the glass (h)armonica is a friction idiophone in which sound is produced by solid matter (glass), not liquid, even though liquid (water) is often present on the fingers of the armonist. The crystallophone is also an idiophone, in which water is used to change the tuning, but not to produce the actual sound. Thus hydraulophones form a unique class of instruments in which sound is actually produced by the water itself.

Relationship to the pipe organ

Many hydraulophones include a separate water-filled pipe for each note, and have sound-production means similar to pipe organs (but with water rather than air), while maintaining the flutelike user-interface (finger embouchure holes).

This form of hydraulophone is similar to an organ, but has water flowing through the pipes instead of air flowing through the pipes.

Relationship to the piano

On a concert hydraulophone, the finger holes are arranged like the keys on a piano, i.e. there is a row of uniformly spaced holes close to the player, and a row of holes that are in groups of 2, 3, 2, 3, ..., a little further from the player. Whereas the piano and organ both have a similar kind of keyboard layout, the response ("key action") is different. Pianos tend to respond to velocity (how quickly a key is struck), whereas organs tend to respond to displacement (whether or not a key is pressed down). Hydraulophones tend to respond to absement (the time-integral of displacement), as well as to displacement, velocity, and to some degree jerk and jounce [http://wearcam.org/acmmm2006/] .

Relationship to instruments that use other states-of-H2O

The hydraulophone uses liquid, typically dihydrogen monoxide (H2O) in its liquid-state (i.e. water). It is thus related to the pagophone, an instrument that uses H2O in its solid state (i.e. ice), and the calliope, an instrument that uses H2O in its gaseous state (steam).

World's largest hydraulophone

Presently the world's largest hydraulophone is the main architectural centerpiece out in front of the Ontario Science Centre, one of Canada's landmark architecture sites. It is also Toronto's only freely accessible aquatic play facility that runs 24 hours a day.

Markings on standard 12-jet hydraulophone

Because the water-spray from hydraulophones obscures vision (or when played underwater where visibility is poor), finger holes are sometimes encoded in Braille. Braille has the added advantage that the one-to-one correspondence between letters and numbers is the same as the standard A-minor hydraulophone, i.e. jet 1 is A, jet 2 is B, jet 3 is C, etc.. The skill (intricate sense of tactility) needed to play a hydraulophone well is also similar to the skill needed to read Braille.

(12 sets of dots made from metal pins below each finger hole)

References and notes

External links

*http://www.funtain.ca -- FUNtain makes and sells hydraulophones.
*http://wearcam.org/osc/opening -- Site devoted to world's largest hydraulophone, including opening day celebrations, etc..
* [http://www.ontariosciencecentre.ca/tour/teluscape/default.asp Ontario Science Centre website for Teluscape and its main centerpiece, the circular hydraulophone sculpture.]
* [http://hackedgadgets.com/2007/02/17/ontario-science-centre-hydraulophone-musical-keyboard-water-fountain/ Hacked Gadgets article on hydraulophones]