Hyperpiano
Extended Piano Performance Techniques

by Denman F. Maroney

Testimonials
Overview
Influences
General Considerations
Tools
Copper Bars
Tibetan Singing Bowls
Rubber Blocks
Plastic Cassette and CD Boxes
Plastic Bottle
Mallets
Cow Bell
 
 
 

Photo: Sheila Schonbrun

[An edited version of this article was published in the March '99 issue of Downbeat.]

Testimonials

Charles Flaum, Registered Piano Technician
Carleton Macy, Macalester College
Patrick Frisco, New Music Society, Dearborn MI
Stephen K. Dove, Steinway & Sons

Overview

When a piano is played the way it is supposed to be played, the keys are depressed, indirectly causing the hammers to strike the strings. But a piano can also be played by stopping, sliding, bowing, plucking, strumming and striking the strings directly with a variety of tools including bars, bowls, knives, bells and mashers of metal, boxes and bottles of plastic, mallets of various kinds, and blocks of rubber. This article explains these techniques, which collectively I call "hyperpiano." Conventional piano music is made from a palate of 88 pitched tones having a particular timbre and envelope. Hyperpiano music is made from a much larger palette in which these tools are used to alter the pitch, timbre and envelope of those tones.

Influences

Playing inside the piano per se is nothing new.

In certain piano music of Henry Cowell, strings are excited directly with the fingers. In The Banshee, for example, the sustain pedal is depressed, and strings are rubbed or scraped. In Aeolian Harp, keys are depressed silently to lift the dampers, and the associated strings are strummed.
 

In the "prepared piano" music of John Cage, strings are prepared in advance by inserting nuts, bolts, clips, rubber bands and the like between strings at precisely specified points to produce various percussive timbres when played from the keyboard in the usual way.

In certain music of George Crumb, piano strings are excited with various objects in various ways, separately and in conjunction with regular keyboard playing.

In the "bowed piano" music of Stephen Scott, strings are bowed with strands of various kinds of string or wire by an ensemble of players.

These are just a few examples.

General Considerations

The piano is built to be played from the outside i.e. the keyboard only. By playing from the inside you risk doing it damage. But if you apply the techniques described below carefully and correctly, you do no damage, and you can make a wide variety of interesting and beautiful sounds.

Sound quality aside, a straight strung 6-foot grand (more or less) is ideal for "hyperpiano" playing, because it affords the most access directly to the strings. Straight stringing is ideal, because no strings are obstructed by others. On a 6-foot grand you can reach not only the center node (and hence all the partials) but also the entire length of most strings. A grand is ideal, because the string plane is horizontal, so gravity is with you.

But sound quality is paramount, and longer strings sound better and speak louder. Hence concert grands are 9-foot, and straight stringing is obsolete, because overstringing affords longer strings in pianos of equal length.

Parts of all strings on all pianos are obstructed by the dampers and plate. But damper placement and plate design vary, so some techniques work better on some pianos than others. Plates are cast or welded, but some have a removable bar attached with screws to the struts that straddle the middle register. For "hyperpiano" playing, this bar is best removed. Before you try to remove it, you should talk to your host about it. If you can unscrew the screws and lift it off with ease, you can safely leave it off (but be sure to replace it when you are done). If not, you should put it back if you got it off, replace the screws if you got them out, and work around it.

All piano strings have suspended and non-suspended parts. Only the suspended parts sound. The primary suspended parts are the parts between the guide bars and bridges that are struck by the hammers when the keys are played. The secondary suspended parts are the parts between the tuning pins and guide bars in front and the bridge and hitch pins (the duplex scale) in back. The non-suspended parts are the parts on the tuning pins, guide bars, bridge pins, bridges, aliquot bars (if any) and hitch pins.

There are many ways to excite a string including stop, slide, bow, pluck, strum and strike. The meanings of these terms are well known, but just to avoid any ambiguity: to stop is to press on (more on this in a moment), to slide is to move along, to bow is to move across, to pluck is to pull and release, to strum is to stroke multiple strings, and to strike is to hit.

A piano has no fingerboard. As such a piano string cannot be stopped completely. The harder the material of the tool you use, the closer to a complete stop you can get. When a string is stopped anywhere along its primary suspended part and then excited, complementary partials are produced, whose pitches correspond to the fractions of string length on either side of the stop point.

Depending on how a stopped string is excited, complementary partials of unequal loudness are produced. With keyboard action, louder partials emanate from the fraction struck by the hammer. With a tool alone, louder partials emanate from the longer fraction.

Stop a string at the center node (equidistant from the ends of the primary suspended part), and you get complementary partials whose pitches are equal, and of which the loudest are equal to the octave (second harmonic). Being equal in pitch, these partials reinforce each other dynamically, making a louder sound. Stop a string at one third its length, i.e. at the fifth (third harmonic), and you get complementary partials, of which the loudest are an octave apart. For example, if you stop the strings of C2 (two octaves below middle C) at one third their length, the loudest partials you get are G3 and G4. And so on.

Sliding a tool makes the complementary partials slide in contrary motion. After striking a key, sliding a tool toward an end (away from the hammer strike point) makes a louder descending slide (by lengthening the fraction struck by the hammer) and a softer ascending slide (by shortening the other fraction). As the tool nears an end, the respective fractions approach one and zero; the respective dynamics, one and zero (maximum and minimum); and the respective partials, one (the fundamental) and infinity. Thus, sliding from an end (toward the hammer strike point) has the effect of bending the fundamental, because the complementary partials are inaudible in both loudness and pitch.

Pianos have wound bass strings and unwound treble strings. Slide an edge of a tool (if any) on a vibrating wound string, and you get sound not only from the fractions of string length on either side of the stop point, but also from the edge of the tool catching the winding at the stop point.

Just as violinists vary their sound by bowing over the fingerboard, on the bridge, with the wood and so on, you can vary the sound by where and how you use a tool, the amount of tool area you apply, the amount of pressure you use, the angle you use and so on.

Tools

The tools I use include:

       2 rectangular copper bars, both 6 inches long, 1.75 inches wide and 5/8 inches thick.

       2 solid steel cylinders 6 inches long and 2 inches in diameter (very heavy)

       3 Tibetan singing bowls of various sizes.

       2 rectangular sheets of reinforced rubber (made from tire tread) approx. 6 in. long, 3 in. wide and 3/8 in. thick.

       2 rectangular plastic audio cassette boxes with protruding lids, and 2 CD boxes.

       1 plastic bottle with opposing curved and indented flat sides. It is 8.25 inches tall, 3.5 inches wide, and 3 inches thick. The mouth is 2.25 inches in diameter. It also has a lid, which I don't use.

       2 pairs of marimba mallets, one with yarn heads and plastic handles and one with rubber heads and wooden handles.

       1 copper cow bell with clapper.

Copper Bars

From a performance (as opposed to geometry) perspective, each bar has 3 faces and 4 edges, since, like any rectangular object, each face and edge has an equal and opposite equivalent. Depending on the musical context, use any face or edge to stop, slide, bow, pluck, strum or strike any part of a string. You get a louder sound with an edge than a face and with a side than a top or bottom face. This is because an edge has a smaller area than a face, and a short (end) face has a smaller area than a long (side) face.

To bend a note (change its pitch slightly from the fundamental) with a bar, stop its string(s) close to the front or back of the primary suspended part(s), strike its key and slide the bar toward the center of the string(s). Like a violinist, you get a different timbre from the back, close to the bridge. If you let a bar touch the bridge pins, you alter the sound considerably. If you hold a bar at a vertically small (close to horizontal) angle, you cause the strings to touch the bridge as the bar passes over it. This adds a wooden timbre that rises in pitch as the bar approaches the bridge pins.

In any register you can bend any note uniformly by sliding a bar on all its strings. In the lower bass, where there is one string per note, you can only bend a note uniformly. In the higher bass, where there are two strings per note, you can detune a unison diad by applying a bar end at a vertically diagonal angle and sliding one string. Higher up, where there are three strings per note, to detune a unison diad, depress the soft (una corda) pedal (so the hammer strikes only the upper two strings), apply a bar end at a vertically oblique angle and then slide the upper string. To detune a unison triad, slide either an end on the highest or lowest string or a corner between any two strings. The former effect is more subtle, because it affects only one string out of three.

An end (short side) of a bar spans the strings of 3 keys (a whole step) at once when put straight across the strings (at a horizontally perpendicular angle). At progressively smaller angles spans progressively fewer strings, down to a minimum of the string(s) of one key (at a horizontally parallel angle). Its edge can be used to span fewer than the multiple strings of one key.

When put straight across the strings, a side (long dimension) of a bar spans the strings of 10 keys (a major sixth). In the middle register, on overstrung pianos, a side spans more strings in front, because these strings are not strung parallel but fan out in back.

The intervals of the partials that sound when the strings of a given keyboard diad are stopped depend on the stopping points. Sliding the same distance at a fixed angle makes the partials of the higher strings slide further, because the strings of the higher note are shorter.

The sounding intervals of a given keyboard diad depend upon a bar's horizontal angle of application. For example, suppose you stop the strings of the keyboard diad C4-E4 with a side of a bar. When you put a bar side straight across the strings, at a point where the low end stops the center nodes of the strings of C4, the sounding intervals of the louder and softer partials respectively are approximately C5-C#5 (a half step) and C5-G#5 (a minor sixth). Rotate the bar clockwise, and the interval of the louder partials widens; counterclockwise, the interval narrows. (The reverse is true of the softer partials.) To sound the diad C5-E5, stop the center nodes of the strings of both C4 and E4. To do this, put the bar side at an angle roughly parallel to the treble bridge and 45 degrees to the strings.

Strike a key and then quickly stop its string(s), and you get the fundamental followed by the partials of the longer fraction. Strike the key of the stopped string(s) again, and you get mainly the partials of the fraction struck by the hammer. If the stop point is in front of the damper, the two sets of partials are the same. If the stop point is behind the damper, the two sets are complementary.

You can stop strings more completely with an end than a side, because you can apply more pressure with an end, which has a smaller area. For the same reason you can stop strings more completely with an edge than a face.

You also can use bars to bow the primary suspended parts of strings.

Unlike violin strings, piano strings lie in one plane, so they cannot be bowed individually with a bar. How many can be bowed at once is determined by the length of the bar.

You almost always have to lift the dampers of strings you want to bow. Depending on the musical context, you can do this by either striking and holding down keys, depressing keys silently or sustain pedaling.

Bow with a side of a bar, not an end. To bow wound strings, use a face, not an edge, and a side face, not a top or bottom face. To bow treble strings, use an edge, not a face.

The bowed sound is affected by the state of the strings, the pressure applied, the stop points, and the direction and speed of bowing. More bow pressure makes a louder sound. The stop points determine the harmonic content, for the bar stops as well as excites the strings.

In general it is best to bow straight across (horizontally perpendicular to) the strings. To some extent, changing the bowing angle changes the harmonic content of the sound. Bowing at too small an angle produces no sound.

By bowing faster or slower you make a louder or softer sound. Bowing too slowly produces no sound.

In addition to varying the stop point, vary the harmonic content by depressing keys silently to lift selected dampers instead of sustain pedaling to lift them all. On really responsive pianos you can can bow chord progressions in this way. (But when you bow the strings of, say, a C major triad, you hear far more than C major.)

Strike the keys of bowed strings to get a sforzando effect.

Strike and hold down a key, cluster or chord and then quickly bow its string(s), and you get percussive fundamentals followed quickly by bowed partials.

Tremolo bowing at various speeds is effective on the treble but not the wound strings. It works at any angle or speed with or without sustain pedal. It even works in circles.

You also can use bars to pluck, strum and strike the strings.

One way to do this is to hold one corner loosely with a thumb and finger and let the diagonally opposite corner bounce from string to string. Do this on suspended and non-suspended parts of strings. Do it very gently.

On the primary suspended parts, a bouncing bar makes a sort of glissando, in which each note sounds as often as it has strings. Follow the bouncing bar (so to speak) by simultaneously playing more or less chromatically at the keyboard, and you can get a shadow or echo effect.

On the secondary suspended parts, a bouncing bar makes a variety of delicate sounds of ambiguous pitch. In front (between the tuning pins and guide bars), it makes a mixture of very low and very high sounds, because the corner bounces on the plate as well as strings. In back (on the duplex scale), it makes only very high sounds.

On the non-suspended parts, between the bridge pins, a bouncing bar makes a loud wooden sound. On the guide bars, bridge pins, aliquot bars and hitch pins, it makes various metallic sounds. Never bounce a bar on the tuning pins.

Another way to pluck, strum or strike with a bar is to hold one end at a vertical angle perpendicular to the strings, drop it on the primary suspended parts and then either catch it or let it bounce. If you let it bounce, make a circle around it with your thumb and forefinger to keep it from falling. You get a nice effect by lifting the dampers at some point after you drop a bar and before it stops bouncing.

Draw a side of a bar over the primary suspended parts at a horizontal angle nearly parallel to the strings, so it catches on them. This produces a drunken pizzicatto effect.

Steel Cylinders

From a performance perspective a cylinder has only one edge and two faces, of which the end is flat and the side is round. Cylinders are used to stop, slide, or bow the primary suspended parts of strings. Having fewer edges and faces than a bar, a cylinder might seem less versatile, but, being heavier, it can stop the strings more completely with less pressure. The round face can be rolled along the strings, producing smoother slides in pitch.
 

Tibetan Singing Bowls

Singing bowls are used to slide and strike the strings.

On most pianos, bowls can be used only on the primary suspended parts behind the dampers, because the dampers and plate block their access to the front end of the strings.

The main way to use a bowl is to hold it by a side and slide the bottom on the strings. Timbral variations are possible by changing the angle of application. Hold a bowl by a side and press your fingers on the inside bottom to mute the sound. Leave a bowl on the strings and maneuver it with a bar pressed on the inside. This makes a timbre that varies according to how the bar and bowl as well as bowl and strings interact.

Another way to use a bowl is to drop or throw it (gently) onto the strings and let it bounce. Drop it straight down, and it bounces on a basically fixed set of strings. Throw it or drop it with a twisting motion, and it travels as it bounces.

Drop a smaller bowl inside a larger one resting on the strings.

Play a kind of 3-card Monte game in which you cover a smaller bowl with a larger one and then rattle it by sliding the larger one against it.

Rubber Blocks

Use a side or face of a rubber block to stop and slide strings.

When put straight across the strings, a side of a block spans the strings of 9 keys (a minor sixth); an end, 5 (a major third).

Rubber is softer than metal, so when you stop strings with a block and play the associated keys, you get higher partials only.

Slide a block on the strings of keys you play, and you make a panoply of higher partials slide in contrary motion. On wound strings, the block itself makes a rubbing sound when you slide it slowly and a whipping sound when you slide it quickly and lift it off at the end. The whipping sound is reminiscent of Henry Cowell's Banshee.

Plastic Cassette and CD Boxes

Audio cassette boxes have a variety of designs. Use the kind that have squared edges and a protruding lid.

Put straight across the strings, the lid spans the strings of 7 keys (a tritone).

Use the edge of the lid to slide and bow the primary suspended parts of strings. Use the lid because it is free to move to some extent. Friction makes it vibrate on the strings, like the hair of a violin bow.

Slide a box lid to produce a sliding cluster. On some pianos, you have to strike the strings at first to get them excited (so to speak), but on others you can make a slow attack. On most pianos, you can vary greatly how fast you slide; on some, you can slide in one direction for a minute or more. At this rate, the slide (pitch change) is barely perceptible; the sound resembles an off stage choir of English horns sustaining a tritone cluster.

Sliding on wound strings, the lip makes a discontinuously popping or continuously scraping sound, depending on how fast you slide.

Rotate a box back and forth as you slide. This produces alternately higher and lower register clusters.

Bowing with a box makes a soft, scraping sound.

At certain angles to the strings you can bow and slide simultaneously.

Plastic Bottle

Like the rubber blocks, the bottle is used to stop and slide strings. Plastic, like rubber, is softer than metal, so when you play the keys of strings you stop with a bottle, you get only higher partials. The bottle has curved and flat surfaces, so applying it at different angles makes different timbres. When a long side is put straight across the strings, it spans the strings of 13 keys (an octave). The rim applied flat spans the strings of 4 keys (a minor third). The base applied flat at a horizontal angle 45 degrees; (i.e. with its diagonal perpendicular) to the strings spans the strings of 6 keys (a perfect fourth).

Mallets

Use mallets in three ways: to strike and strum with the heads and to slide with the butts.

To strike and strum strings are self explanatory. You also can strike the plate and case, but only with yarn heads. Never strike dampers. Trill a yarn head between the bass strut of the plate and the case.

To slide, put a mallet butt between two unison strings; the gap between non-unison strings is too wide. The sound has a slow attack and a feline quality. On some pianos you can slide slowly enough to produce a sustained instead of sliding pitch. Slide slowly back and forth to produce a slow vibrato. Slide on the duplex scale and aliquot bars to make high and rather random pitch patterns. Never slide on the plate or soundboard.

Cow Bell

Use the rim of a cow bell to stop and slide the primary suspended parts of strings. Apply the bell at vertically oblique angle (so only part of the rim stops the strings) and then rock or slide it in spurts to make the clapper strike the bell.