Wikipedia Deep Dive

Prepared piano

11 min read

Imagine walking into a concert hall, settling into your seat, and watching a pianist reach inside the grand piano with a handful of bolts, rubber erasers, and what appears to be a chain of paper clips. This isn't vandalism. It's preparation.

The prepared piano is exactly what it sounds like: a piano that has been altered by placing foreign objects on or between its strings. The result transforms one of Western music's most familiar instruments into something entirely alien—a single performer commanding what sounds like an entire percussion orchestra, each key producing its own unique, often unrecognizable timbre.

The Necessity That Invented an Art Form

In 1940, John Cage faced a problem. He had been commissioned to write music for a dance piece called Bacchanale, choreographed by Syvilla Fort. For years, Cage had been composing exclusively for percussion ensembles—those sprawling groups of drummers and cymbal-crashers and mallet-wielders that could fill a stage with noise and rhythm. But the Seattle venue where Fort's dance would be performed had no room for such an ensemble.

All Cage had to work with was a single grand piano.

Most composers would have simply written a piano piece. Cage did something different. He realized he could place objects inside the piano—on the strings, between them, against the hammers—and transform that lone instrument into something capable of producing the varied, percussive sounds he needed. As he later put it, he could "place in the hands of a single pianist the equivalent of an entire percussion orchestra."

The idea wasn't entirely without precedent. Cage himself credited the composer Henry Cowell as his primary inspiration. Cowell had pioneered what he called "string piano" techniques in the 1920s, reaching inside the instrument to pluck, sweep, scrape, and thump the strings directly rather than using the keyboard. His pieces Aeolian Harp and The Banshee had already demonstrated that a piano could be so much more than a keyboard instrument.

But Cage went further. Where Cowell had manipulated the strings with his hands during performance, Cage prepared the piano beforehand, inserting objects that would alter the sound of specific notes throughout the piece. This allowed for a kind of composed unpredictability—each key would produce its own characteristic timbre, and the original pitch of the string might not be recognizable at all.

A Brief History of Putting Things in Pianos

The impulse to alter a piano's sound actually predates Cage by decades. Early in the twentieth century, composers experimented with placing pieces of paper on piano strings to create a buzzing effect. This wasn't entirely new either—it echoed the "bassoon pedal" found on early fortepianos, which pressed parchment against the strings to produce a similar sound.

The French composer Maurice Delage, working on a piece called Ragamalika between 1912 and 1922, specified that a piece of cardboard should be placed under the B-flat in the bass register to dampen its sound. He was trying to imitate an Indian drum. The Brazilian composer Heitor Villa-Lobos, in his 1925 work Chôros No. 8, instructed the second pianist to insert pieces of paper between the strings. Maurice Ravel, in his opera L'enfant et les sortilèges, called for an instrument called a Luthéal—essentially a modified piano—but allowed performers to substitute a regular piano with paper preparations.

None of these experiments developed into a systematic technique the way Cage's prepared piano would. They were isolated moments of timbral color. Cage made preparation itself the point.

The Sound of Objects

What does a prepared piano actually sound like? The answer depends entirely on what you put inside it and where you put it.

A bolt placed between two strings might produce a metallic, gamelan-like tone—think of Indonesian percussion instruments with their shimmering, bell-like quality. Rubber erasers can mute a string almost completely or give it a deadened, woody thump. Screws change the resonance in ways that can make a piano sound like it's underwater. The una corda pedal—the leftmost pedal on a grand piano, which shifts the hammers so they strike fewer strings—adds another layer of variation.

Cage's Sonatas and Interludes, composed between 1946 and 1948, represents perhaps the most thorough exploration of the prepared piano's possibilities. The piece requires detailed preparation of 45 notes using various objects, and the resulting sound world is unlike any other keyboard music. Some notes ring and shimmer. Others thud. Some seem to bend pitch in impossible ways. The piano becomes an orchestra of one, but an orchestra from another planet.

The crucial point—and this distinguishes prepared piano from simply destroying an instrument—is that the preparation should be reversible. When a properly prepared piano has been "unprepared," it should be impossible for anyone to tell that it had ever been altered. The objects sit between or on the strings without damaging them. This is a temporary transformation, not a permanent modification.

The Tack Piano: A Different Kind of Altered Instrument

Not all modified pianos qualify as prepared pianos, strictly speaking. Consider the tack piano, which you might recognize from old Western movies or ragtime recordings—that honky-tonk sound where each note seems to have a bright, almost metallic attack.

A tack piano achieves its distinctive sound through metal tacks or nails driven into the piano's hammers. When the hammer strikes a string, the metal tack contacts the string before the felt does, creating that characteristic brightness and sustain.

But this technique fails two important criteria for prepared piano. First, the original pitches remain completely perceptible—it still sounds like a piano, just a different kind of piano. Second, and more critically, the preparation isn't truly reversible. While you can remove the tacks, inserting them permanently damages the felt hammers. For this reason, piano technicians generally discourage the practice, and instruments used as tack pianos are typically dedicated to that purpose permanently.

From the Concert Hall to the Recording Studio

The prepared piano didn't stay confined to the avant-garde. Its techniques spread into popular music, easy listening, rock, and electronic genres—sometimes in places you might not expect.

Ferrante and Teicher were an American piano duo who seemed unlikely candidates for experimental techniques. They specialized in light classical arrangements and easy listening music, producing over a hundred albums during their career from 1947 to 1992. Yet between 1950 and 1980, they regularly used partially prepared pianos to add percussive effects to their recordings. The prepared piano had found its way into the most middle-of-the-road music imaginable.

In 1967, John Cale—not to be confused with John Cage—prepared his piano with a chain of paper clips for "All Tomorrow's Parties," one of the most haunting tracks on The Velvet Underground's debut album. The preparation gives the piano an almost harpsichord-like quality, brittle and persistent.

Dave Brubeck, the jazz legend, prepared a piano by laying copper strips across the strings for his 1968 album Blues Roots, aiming for a honky-tonk sound without permanently modifying an instrument. Brian Eno employed prepared piano on his 1975 album Another Green World and later on David Bowie's Lodger in 1979.

The technique proved surprisingly versatile. Richard James, recording as Aphex Twin, incorporated prepared piano into several compositions on his 2001 album Drukqs, integrating acoustic experimentation with his electronic productions. The German composer Hauschka—real name Volker Bertelmann—built an entire career around prepared piano, releasing an album literally titled The Prepared Piano in 2005 and going on to compose film scores using the technique.

Hyperpiano and Other Mutations

Some performers have pushed the concept so far that they've invented new names for what they do.

Denman Maroney calls his instrument the "hyperpiano." His technique involves stopping, sliding, bowing, plucking, striking, and strumming the strings with copper bars, aluminum bowls, rubber blocks, plastic boxes, and various household objects. It's somewhere between Cage's careful preparations and Cowell's direct string manipulation, creating sounds that seem to have nothing to do with the familiar piano at all.

Cor Fuhler pioneered numerous inside-piano techniques during the 1980s, developing approaches that went well beyond simple object placement. Roger Miller—the indie rock musician, not the country singer—has been developing his own take on prepared piano since 1982, initially with the post-punk band Mission of Burma. His concert hall compositions since 2009 have often featured prepared instruments.

Kristin Hayter, performing as Lingua Ignota, has toured with a piano prepared with forks, clothespins, fishing wire coated in heavy rosin, bells, chains, and a clamp lamp. Her music combines classical training with industrial noise, and the prepared piano becomes a vehicle for sounds that range from delicate to brutal.

The Acoustisizer: Preparation Meets Electronics

In 1983, a graduate student named Bob Fenger at California State University Dominguez Hills created something that pushed the prepared piano concept into entirely new territory. His thesis project, the Acoustisizer, started with a small grand piano but added built-in speakers, magnetic guitar pickups, and piezoelectric contact microphones.

The speakers were built into the bottom of the instrument, redirecting its own amplified sound back onto the sounding board. This created a feedback loop—the strings would vibrate, be picked up by the microphones, be amplified, and the amplified sound would cause the strings to vibrate again. Fenger suspended what he called "kinetic oscillators"—assemblages of vibration-sensitive materials—from the instrument, which would respond to this feedback with their own movements and sounds.

The Acoustisizer represented a fusion of acoustic preparation with electronic processing, creating an instrument that could generate sustained, evolving sounds impossible on an unmodified piano. It was a prepared piano that prepared itself.

The Philosophy of Alteration

There's something philosophically interesting about the prepared piano. It takes one of Western classical music's most standardized, most precisely manufactured instruments—an instrument whose whole design philosophy involves consistency and predictability—and makes it unpredictable.

Think about what a modern concert grand represents. Every piano from a given manufacturer is built to exacting specifications. Pianists expect to be able to sit down at any Steinway or Bösendorfer and find fundamentally the same instrument. The piano standardized pitch, standardized keyboard layout, standardized the very idea of what a keyboard instrument should be.

The prepared piano rejects all of this. When Cage prepared a piano, he was creating a unique instrument that existed only for that performance. The specific placement of objects, the particular piano used, the exact materials chosen—all of these combined to create an instrument that had never existed before and would never exist again in quite the same way.

This impermanence was part of the point. Cage was deeply influenced by Zen Buddhism and the idea of impermanence, of accepting the sounds that exist in the moment rather than imposing a predetermined structure. The prepared piano was a philosophical statement as much as a musical technique.

How to Prepare a Piano (Without Destroying It)

If you're curious about preparing a piano—and own one, or have permission to modify one—the basic technique is straightforward, though mastering it takes considerable experimentation.

The standard approach involves placing objects between adjacent strings or between the string and the hammer. Bolts and screws can be threaded between strings at different points along their length—closer to the hammer produces one effect, closer to the tuning pins another. Rubber or felt can be woven between strings to dampen them. Paper or plastic can be placed on top of strings to create buzzing effects.

The key is reversibility. Never use anything that could scratch, dent, or otherwise permanently alter the strings or soundboard. Never force objects in so tightly that they can't be easily removed. Never use adhesives or anything that might leave residue.

And if you damage the piano? Well, then you haven't prepared it. You've just broken it.

The Prepared Piano's Legacy

More than eighty years after Cage first prepared a piano for Syvilla Fort's dance, the technique remains vital. It appears in contemporary classical composition, film scores, rock music, electronic productions, and performance art. It has inspired prepared guitar, prepared harp, and prepared versions of virtually every stringed instrument.

Perhaps most importantly, the prepared piano changed how we think about instruments themselves. It demonstrated that an instrument isn't just a fixed set of sounds waiting to be deployed. It's a starting point, a possibility space that can be altered, extended, transformed. The instrument doesn't dictate what sounds it can make. The performer does.

John Cage, asked once about his prepared piano work, described it this way: "I was disturbed both in my private life and in my public life as a composer. I could not accept the academic idea that the purpose of music was communication." He wanted music that existed for itself, sounds that were interesting without needing to say anything.

Put some bolts in a piano, and suddenly it stops communicating the way you expect. It starts making its own sounds, following its own logic. The performer gives up some control. The instrument gains some agency.

That exchange—the willingness to let an instrument become something you didn't plan, couldn't predict, might not even fully understand—remains the prepared piano's most radical contribution. It's not just a technique. It's a different way of thinking about what music can be.