HPSCHD is a large and complex multimedia work, carried out by two particular stars of American music: John Cage, among the most controversial composers of the twentieth century, and Lejaren Hiller, a pioneer of computer music.

Describe in a few words what is HPSCHD, it’s impossible, because its complexity; and could not be otherwise because the cultural and professional background of the authors of this work that I have just now categorized with the label “media”, certainly appropriate for a work that combines, in a single performance space, traditional instruments, digital synthesis, video materials and photographic projections.

Not only is it difficult to find a succinct definition, but also organize a lot of information regarding the different characteristics of HPSCHD, rearranging the readings of the documents that I have used for the preparation of this article.

Why? – Before getting on specific issues related to the work, I would like to clarify the path that led to the composition of this work, which is far from clear. Just as I would like to explain why they came to conceive a work which tied together two such different instruments: the computer, no doubt as the most advanced technological thrusts, and the harpsichord, which more than many other instruments brings memories of a remote past.

In the path of creating HPSCHD, certainly was very important the context of festivities that was created for the centenary of the University of Illinois at Urbana-Champaign, from 1967 until the end of the following year. In fact, the University was founded in 1867 but the educational activities were started only as of 2 March 1868. In that way Cage has entered into these celebrations is a matter not always clear: in a recent biography, Kenneth Silverman writes that Cage only thanks to an invitation as a guest professor met Hiller and attend a two-week seminar on computer music [Silverman], I read elsewhere that it was the University, in the person of Hiller, to contact Cage to propose the composition of two works based on the use of computers and random procedures [Husarik] instead Hiller recalls in an interview that was Cage to contact him by phone, by expressing the desire to compose something with the computer and asking him if there was a possibility of a collaboration within the University; so Hiller proposed John Cage as a member of the Center for Advanced Study of Illinois for the year 1967/68 [Hiller].

Beyond these different evidences, certainly there is that the University of Illinois was a great place to engage in the composition of computer music, in fact Hiller was a good pioneer, because in the fifties he composed the Illiac Suite. It also seems that John Cage, regardless if it was a proposal or a request of the University, came up with an idea of two new works: Atlantis Borealis With the Ten Thunderclaps and HPSCHD.

John Cage and Lejaren Hiller working for HPSCHD.

Why HPSCHD? – Hiller put available to Cage not only the equipment available in those years, but also its staff, which would follow the implementation of the two computer work, since in those years few composers had acquired some expertise in the digital environment. Of the two works, only HPSCHD was completed; Atlas Borealis at that time remained only the title, perhaps also due to the considerable complexity of the other work.

HPSCHD owes its title to a previous commission that John Cage had received and that he had not still not satisfied. The Swiss harpsichordist Antoinette Vischer was a proponent of a commissions project of new works dedicated to the harpsichord, and in the course of a few years has involved composers such as Luciano Berio, Earle Brown, Hans Werner Henze, Duke Ellington and, in fact, John Cage. Even the American harpsichordist Sylvia Marlowe made a proposal similar to that of Vischer [Kostelanetz, 2005].

a picture of Antoinette Vischer, shooting at the harpsichord in the evening of the premiere, May 16, 1969.
a picture of Antoinette Vischer, shooting at the harpsichord in the evening of the premiere, May 16, 1969.

In both cases, Cage seemed to take time, and the reason was quite simple: did not particularly like the timbre of the instrument [Austin]

I must admit I’ve never particularly  liked the instrument. It sounded to me like a sewing machine. John Cage

LThe situation created by Hiller in Urbana, it seemed appropriate to combine the two. The name itself derives from the commission of Vischer, in fact HPSCHD is a contraction of the word harpsichord, to pronunce hip’-see-kid or simply harpsichord, as Cage preferred [Kostelanetz, 1989].

The computer – Imposed the computer, in one way or another, as a prerequisite of this work, Cage did not just consider using it as an automatic machine only, rather wanted to set the work to make it indispensable for the purposes compositional places. For this reason, the design of the project was that the machine would allow you to create something that was not possible to do otherwise.

“…and so I thought of this as a useful project in relation to the computer, because it made possible something that was otherwise wery difficult”. John Cage

Why Hiller? – Until now I have repeatedly made reference only to the person and to the intentions of Cage, ignoring the contribution of Hiller. It is not accidental: initially the work should have only the paternity of Cage, and the University of Illinos would provide the technical support of the programmer Gary Grossman. Undertakings of the latter shall hindered the availability and for this it was necessary the involvement of Hiller, who was presented with a technical proficiency but also creative, being also a composer. The collaboration was so close that Cage proposed both names for the credits work.

Mozart – This delayed involvement in the project, explains why some starting ideas were mostly developed by John Cage. The starting point, what the composer calls “the original idea”, comes from his personal conception of music by Mozart that he sees as a unit that develops from the combination of several musical elements, also very different. A process that Cage intends to push to the limit, thanks to the possibilities offered by the computer. The goal was to multiply the details of pitches and durations of sounds.

I-Ching – The second peculiarity of the project is that of randomness. Needless to say, John Cage drew those eastern procedures already adopted from the fifties through the I-Ching. The studies of Buddhist philosophy and Zen made in those years with Daisetsu Suzuki, prompted him to groped a liberation of music from the constraints of their own culture and their own interests, which are also culturally conditioned. The answer to this attempt came via the I-Ching, a text that allowed the consultation of oracles to interpret through six launches of three coins, which you can select one of the 64 hexagrams which consisted of the Book of Changes. Cage used it the first time for Music of Changes (1951/52). For HPSCHD, Hiller and Cage had to transfer in computer information HPSCHD this ancient Chinese tradition.

Musikalisches Würfelspiel – In addition to the procedure of the I Ching, the two composers realized this ambitious project and relying on another random procedure as historicized and known: the Musikalisches Würfelspiel by Mozart, in english Dice Game: a method that allowed to generate music by random, using only dices for the selection of pre-formed musical elements, for example small musical sections to be combined together to make larger structures.

Instruments – The above, is the cultural and conceptual foundation on which the two composers realized the entire work. In addition, there are two aspects that need to be clarified before any other: the ensemble, and, closely related to it, the role of the computer.

The Vischer’s commission, which I mentioned earlier, expressly requested that the work was intended for the harpsichord, or at least that the instrument was somehow present. Next to it, a electronic section was scheduled: digital synthesis to be recorded on magnetic tape. Overall, the ensemble was made up of seven performers of the harpsichord, and an orchestra of 51 tapes, each with its own speaker (not all documents agree on the number, for example, Husarik writes of an electronics orchestra of 52 elements). The music made on the computer, for each of these performers, was obtained by the use of the Illiac II computer and two original software, designed for the occasion: DICEGAME and HPSCHD.

A picture of the performance of May 16, 1969. Do you see the center of the performers and around the banners and graphics for image projections.
A picture of the performance of May 16, 1969. You can see the performers and, around, banners for graphics and images projections.

DICEGAME – This software, technically a subroutine, was designed specifically for the composition of music pieces performed by the seven harpsichords. Of 176 beats that Mozart created with the dice game, this computer version it retained only 64, because it appeared as a modified version through the logic of the I Ching, each measure had a duration of 1 minute. The computer was programmed so as to perform 20 times the selection procedure of these 64 lines, so as to obtain, for five of the seven harpsichords, the solo parts long 20 minutes. Each of these parties had different features:

– the harpsichord solo II was a performance of the all 64 bars, repeated 20 times;

– similar the solo III, with a twist: a few bars were replaced, by random procedures, with other measures selected from works of Mozart [Husarik]:

Sonata in D Major Maggiore, K. 284 (2nd Movement, first 24 measures)

Sonata in C Major, K. 330 (1st Movement, first 32 measures)

Sonata in G Major, K. 283 (1st Movement, first 47 measures)

Fantasia in C Minor, K. 475 (1st Movement, first 10 measures)

Sonata in B Major, K. 281 (2nd Movement, first 32 measures)

Sonata in D Major, K. 284 (1st Movement, first 32 measures)

– the Solo IV follows the same logic as above but with a complication: the replacement process was done independently for each hand, that is, it could happen that the left hand continued to run the original part and the right part extrapolated a part by Mozart.

– this logic of substitution was also employed for the Solo V and VI, but with a further variant: the material does not original was drawn only from Mozart but also by many other authors, so as to cover, at least ideally, the entire course of music art from Mozart to the twentieth century. The selected works were:

Ludwig van Beethoven, Sonata “Appassionata” N. 28;

Frédéric Chopin, Prelude in D Minor, opus 28;

Robert Schumann, “Reconnaissance” from Carnaval;

Louis Moreau Gottschalk, The Banjo Op. 5;

Ferruccio Busoni, Sonatina N. 2 BV 259

John Cage, Winter Music

Lejaren Hiller, Sonata N. 5

– the Solo VII was marked with a very different logic, and consisted of a single page with instructions reserved to the performer, who could choose for themselves to perform any composition by Mozart or choose one of the performances of the other six harpsichord involved in performance;

– the Solo I, finally, presents very different characteristics compared to all the others. In fact it is a transcription in twelve tones of one of the parties of the tape, which determined a part made very complex for the performer by the presence of numerous and rapid dynamic changes.

A timeline of the composers to use in HPSCHD, with their dates of birth and death. On the right a series of alternatives for a possible replacement of Ives. Manuscript Collection of John Cage's New York Public Library in New York.
A timeline of the composers to use in HPSCHD, with their dates of birth and death. On the right a series of alternatives for a possible replacement of Ives. Manuscript  of John Cage Collection, New York Public Library, New York.

HPSCHD – The second software has the same name of the work, and was designed for the musical parts of the magnetic tape. The acoustic material was synthesized through the use of waves with sawtooth profile, rich in harmonics but especially suitable for obtaining sounds closer to the characteristics of those of the harpsichord. Pitches from which the software could draw, stemmed from a division of the octave in minimum 5 and maximum of 56 parts, which calculated for 64 choices of the I Ching gave back a potential of 885,000 pitches.

The performance – The duration of the parts of the magnetic tape was identical to that of harpsichords, 20 minutes, but this time revolve around different motivations. In fact it should be stressed that the two authors, even before the work was finished, they had signed an incision with Nonesuch Records, which had requested that both sides would not last more than 20 minutes. HPSCHD could occupy only one side or both, for a period that could vary from 20 to 40 minutes in total. But it was possible that a work so complex it did limit by commercial choices? Not really, since Cage and Hiller endeavored the 20 minutes as a true minimum unit, realizing it in a special relationship and microtonal intervals, so they were not willing to segment it, or extend it, according  with values that are not multiples or submultiples of 20.

A picture of the Assembly Hall before the performance. You notice the banner for graphics and video projections.
A picture of the Assembly Hall before the performance. You notice the banner for graphics and video projections.

If the studio version could be limited in the short time of 20 minutes, do not forget that the live project could last several hours. In fact the different parts of 20 minutes could be superimposed vertically, from which the duration of the study in 20 minutes, or juxtaposed horizontally for an indefinite time.

Moreover, even the use of the ensemble could be varied according to requirements. In fact, if the complete version provided all 7 parts of harpsichord and 51 (or 52), magnetic tapes, however it was possible to prepare also lighter versions, as in the case of the studio edition of Nonesuch which was recorded with only three parts of harpsichord.

The cover of the studio HPSCHD, produced by Nonesuch Records.
The cover of the HPSCHD studio version, produced by Nonesuch Records.

Projections – HPSCHD was conceived as a great multimedia show, constituted not only by music but also by a large number of projections, photography and video. The idea was of such complexity that the description of this part of the work is far from simple.

The first person to be involved was Calvin Sumsion, in those years a registered student in the Department of Design at the University of Illinois, and interested in, such as John Cage, the application of random procedures. Sumsion made use of the same data obtained by the two composers with the software DICE GAME. These data were used to determine the location or size of photographs from two encyclopedias and projected onto transparent plastic sheets, hanging from the center of the Assembly Hall.

The graphics were not made only by Sumsion, who also supervised commissions: the first Ronald Resch who was asked to prepare a series of harmonograp, the other to Gary Viskupic who was asked to create a graphic with Cage and behind him a dragon with three heads representing Bach, Beethoven and Schumann.

One of the posters made for the first performance of HPSCHD. The graphics by Viskupic depicts John Cage forward to a dragon with three heads: that of Bach, Beethoven and Schumann.
One of the posters made for the first performance of HPSCHD. The graphics by Viskupic depicts John Cage forward to a dragon with three heads: that of Bach, Beethoven and Schumann.

Other 68 images were obtained from other sources such as NASA, Mount Wilson Observatory, Pagmar and Adler Planetarium. A considerable number of people were involved to make drawings by hand, even Merce Cunningham, while 26 were made by Ron Nametsh. Were used 84 projectors and 100 slides for each projector, for a total of 8400 images.

Nametsh was also in charge of video projections, selecting 400 films of scientific subject, while other material was based on examples of computer graphics, such as by John Witney, whose pieces were combined using random procedures based on the I-Ching. The video projections were done on vertical panels of plastic. The aim of these projections was to tell the story of man from prehistoric to contemporary.

The premiere – The event was held in the Assembly Hall of the University of Illinois, a room for about 17,000 seats that lent itself well to a performance of such complexity, which also ensured excellent acoustics. In summary, for the realization of the entire event were used many elements, whose position was carefully defined by John Cage: 208 magnetic tapes, 84 slide projectors, 51 tape recorders, 52 speakers, 12 video projectors, amplifiers, plastic panels, slides, films, posters and seven harpsichord, played by David Tudor, Antoinette Vischer, William Brooks, Ronald Peters, Yuji Takajasji, Neely Bruce and Philip Corner.

The work of Cage and Hiller would have to complete for the month of March 1968, but in the end there was a shift of more than one year. At 7:30 on 16 May 1969 in front of over 7,000 spectators, were carried out the first electronic sounds. The whole performance, durability indefinable, was also video recorded, and certain technical choices, such as the framing, the selection of filters and other, were subjected to random procedures, in accordance with the methodology applied for the whole project. Unfortunately, nothing of all this documentation has come down to us, because the material was destroyed in a fire that affected the study where the shot had been deposited. However it should be remembered that other executions were organized in the following years, and are organized today, clearly in all circumstances it was adapted to the different requirements.

And now an excerpt of HPSCHD:



Austin, Larry. An Interview With John Cage and Lejaren Hiller, Computer Music Journal, Vol. 16 [4], 1992, pp. 15 – 29.

Cagne, Cole; Caras, Tracy. Soundpieces: Interviews with American Composer, The Scarecrow Press, 1982.

Hiller, Lejaren. Sulla programmazione del Gioco Musicale dei Dadi di Mozart in I Profili del Suono, edited by Serena Tamburini and Mauro Bagella, Salerno 1987, pp. 137 – 157.

Husarik, Stephen. John Cage and Lejaren Hiller: HPSCHD, 1969, American Music, Vol. 1 [2], 1983, pp. 1 – 21.

Silverman, Kenneth. Begin Again: A Biography of John Cage, Northwestern University Press, 2012.

Kostelanetz, Richard. On Innovative Musicians, Limelights ed., 1989, pp. 61 – 67.

Kostelanetz, Richard. Conversing with Cage, Routledge, 2nd Ed. 2005.

  • Hong, Joon Hwa


    My name is Hong, Joon Hwa, and I work as a fine art professor in Keimyung University, South Korea. Recently, I have written a book about contemporary art, and during the process, I had to put a poster of HPSCHD (the last picture in this article) in the book inevitably. Therefore, under the circumstances which do not damage intellectual property rights and the website’s interests, would it be able to put the painting on my book?

    I look forward to getting a favourable reply. Thank you.

    Best regards,
    Hong, Joon Hwa.

  • Hong, Joon Hwa

    To all whom it may concern,
    Nice to meet you. My name is Hong, Joon Hwa, and I work as a fine art professor in Keimyung University, South Korea. Recently, I have written a book about contemporary art, and during the process, I had to put a poster of HPSCHD (the last photo on this page) in the book inevitably. Therefore, under the circumstances which do not damage intellectual property rights and the website’s interests, would it be able to put the poster on my book? I look forward to a favorable response. Thank you.

    Best regards,
    Hong, Joon Hwa

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