The Hyperstring Trilogy

(from Tod Machover's program notes for the Lincoln Center Premiere)

All of my music is somehow biographical, and the Hyperstring Trilogy was composed during a particularly turbulent period in my life, from 1990 to 1993, that started with a broken marriage, moved through serious and unexpected family illness, finally leading to remarriage. New ideas about music, and my relationship to it, accompanied these personal experiences. When I first discussed with Yo-Yo Ma in 1990 the idea of developing a hypercello for him and composing a work for the instrument, I decided to make this the first of a series. I couldn't have predicted the "plot" of my life for the following few years, but did immediately imagine Dante's Divine Comedy as a backdrop for the form and feeling of the three pieces. I also imagined the three as both independent compositions -- with increasingly larger orchestral forces -- as well as three movements of a single work. The three pieces that make up the Hyperstring Trilogy are being performed together, as they were intended, for the first time on tonight's program.

After a series of compositions closely related to the musical ideas and technology of my opera "VALIS" (1987), the Trilogy represented some major new directions for me. Whereas my work from 1986-90 dealt primarily with the bright colors and sharp rhythms of electrified rock music, I tried in the Trilogy to reincorporate the warmth and subtlety of acoustic instruments, and especially strings. In "VALIS" I attempted to create a harmonic and melodic language of extreme directness and simplicity, whereas in the Trilogy contours are more blurred and boundaries more complex. And whereas in the "VALIS" period, my hyper-music was performed by musicians playing on commercially available MIDI controllers (like keyboards, percussion, and guitar), I turned my attention in 1990 to trying to measure the musical expression communicated through string instruments, whose subtlety and richness have usually been beyond the analysis capabilities of digital computers (and their programmers!).

With Joe Chung, I had started the development of Hyperinstruments at the MIT Media Lab in 1986, for the purpose of enhancing and expanding performance virtuosity through technology. Partly motivated by the negative example of sophisticated digital studio recording that risked taking the spontaneity and intuition out of music-making, we sought to develop techniques that would allow the performer's normal playing technique and interpretive skills to shape and control computer extensions to the instrument, thus combining the warmth and "personality" of human performance with the precision and clarity of digital technology. In fact, the whole hyperinstrument idea is an extension of my general musical philosophy: to convey complex experience in a simple and direct way.

Working on hyperstrings, we were able to greatly extend the hyperinstrument model. When Neil Gershenfeld joined the group in 1990, we started to develop sensors to measure the physical gesture of performance; in 1991, Andy Hong brought a sophisticated knowledge of analysis techniques for the acoustic sound of these instruments; and in 1993, Joe Paradiso helped us to "unplug" our hyperstring instruments, making them wireless and therefore even more natural and intuitive to play. Interestingly, this work to develop better techniques for interpreting highly virtuosic performances has simultaneously led us to invent the kinds of natural and intuitive music interfaces found in the Brain Opera hyperinstruments for general audiences.

And also paradoxically (although intentionally), as the Hyperstring Trilogy progresses, more and more diverse musical influences are incorporated into a simpler and more unified musical expression, as more and more sophisticated hyperstring instruments become increasingly absorbed into a blended and seamless sonic whole.

- Note by Tod Machover


Begin Again Again... is the "Inferno" of the trilogy. It was composed for Yo-Yo Ma, who premiered the piece at the Tanglewood Festival in August 1991. The work is scored for solo hypercello, with the performer controlling an array of sound producing and transforming devices. It is about twenty-five minutes long and has ten uninterrupted sections, all distinct in character, which are grouped into two large-scale movements. The first movement is increasingly agitated, energetic, and dramatic; the second is more lyrical, calm and introverted. The title of the piece refers to its musical form and expressive content. Begin Again Again... is a set of variations in which the same melodies and harmonies are returned to over the course of the work, each time expanded and elaborated in new and unexpected ways. Similar to the Sarabande of Bach's Suite No. 2 for Solo Cello (from which the initial ideas for the piece grew), the hypercello line revolves cyclically around the middle D of the instrument, trying constantly to ascend but being ever pulled down to low pedal tones. The hypercello eventually breaks free from the weight of repetition, but not before considerable struggle. As Machover has written: "This serves as a metaphor for change in our lives - of breaking with the past while retaining what is dearest to us; of opening up doors to unknown possibilities; and finally, of renewed hope and affirmation."

In his book, Measure for Measure: A Musical History of Science, Thomas Levenson has described the hypercello and its use in Begin Again Again... as follows:

"The hypercello...serves as the input device to a stack of machines that process the data created by a performer and generate a variety of different types of responses. As the cellist plays the cello, sensors [developed by Neil Gershenfeld] tell one bank of custom electronics the angle the cellist's bow-hand wrist forms, where the bow is on the cello's strings, how much pressure the cellist is placing on the bow, and where the cellist is fingering the strings on the fingerboard. The special circuitry hooked up to the cellist's sensors then translate that analog data into digital information and transmit the results to the system's main computer, which can then transfer that data as MIDI information. At the same time, the electronic signal of the tune actually being played gets fed directly into a synthesizer, which can either manipulate the data or pass it through as a (sort of) conventional cello sound.

"To execute musical functions, Machover and Joe Chung developed a set of software tools to control the flow of information from a performer to his machines. The bow sets up vibrations on the cello's strings - just as in ordinary versions of the instrument - but at the same time it can act as a conductor's baton, with the position of the tip of the bow, the length of the bow drawn across a string per second, the pressure on the bow all controlling musical parameters: the number of musical lines called up from the computer, the timbre of the pitches being played, the attack, and so on. Machover's interest in timbre in particular led to the development of a technique designed to permit the performer to add the pure cello sound coming off the strings to sampled or synthesized timbres stored as MIDI data within the computer, allowing the performer to decide precisely how much of his own playing he wanted to hear. The computer can then generate an accompaniment to the cellist's solo, one whose pace and rhythm would be controlled by the performer. As it executes each of these functions, the main computer processes the data it receives, modifying or even creating sounds, depending on the instructions contained within its software.

"The software here is both part of the instrument, an element of the system that generates a sound, and part of the score, the list of the composer's choices of what sounds should be heard when. The system as a whole thus acts as both an instrument to be played by the performer and as an orchestra responding to the performer's commands, as if the cellist were a conductor as well.

"Begin Again Again... is, like Stockhausen's Kontakte, at once an expression of musical thought and feeling and a report on the current state of the art of the technology of making music."

In fact, Begin Again Again... is, among other things, about the idea of creating a hyperinstrument. It starts out with the performer exerting careful control over the electronic extensions, each bow change, each accent chosen to elicit a specific response. Gradually, however, the computer part starts to develop on its own - as if a Pandora's Box had been opened - becoming denser and more complex than a single human could control. After an explosion at the work's climax, the piece "starts again," tentatively at first, but soon establishing a gentle, balanced dialogue between performer and computer. At the end of Begin Again Again..., a hyperstring instrument has emerged, ready to continue the musical journey of the trilogy, drawing less and less attention to itself.


Song Of Penance, for hyperviola, computer-controlled voice, and 17 instruments, starts with a bang, but soon settles into a still, meditative state from which a process of reawakening gradually blossoms. The work was composed just after Begin Again Again..., and premiered by Kim Kashkashian and the Los Angeles Philharmonic New Music Group (for whom the work was commissioned by Betty Freeman) in February 1992. In order to intensify the purgatorial feeling of the work, Machover requested a text from Rose Moss, a writer with whom he had collaborated several times. Recordings were then made of soprano Karol Bennett, which were mixed, treated, enhanced, and placed in a database, to be called up and manipulated during performance of the piece.

While the measurement and analysis techniques for the hyperviola are similar to those for the hypercello, the use of the instrument is extremely different in Song Of Penance. Besides playing its own melodic line, the hyperviola is "in charge" of the vocal music as well. Soprano words and melodies are initiated by the hyperviola, then shaped and mixed through its phrasing and articulation. Thus a kind of hybrid is created, which combines viola and voice into a single instrument. And just as the hyperviola part is less extroverted than the hypercello in Begin Again Again..., so the vocal music seems to grow directly out of the viola itself, present yet invisible. Machover has written: "While the viola always remains the center of the musical action, I have attempted to create a fluid blending with voice, text and instrumental ensemble. Song Of Penance follows the form of its poem in musical development (which is not surprising, since I worked closely with Rose Moss to shape this mini-libretto!). Although not a long piece, much contrasting musical ground is covered on this journey, which I imagined as one continuous upward sweep: from defeat and pain, to rest and healing, to resolute reconciliation and, finally, to 'peace and play.'"

Song Of Penance by Rose Moss

Going to seed your repenting heart as if alone whirls
in a blizzard
cracked and crazing and stuck on ice
as mute as stone
and lodged in night
whose strict address
of grime and shame tells all
and all avert their eyes from yours
till you, without a name, without a home
a back, a shank
wincing from squalor and rancor
wrest free from locks of pride
and scourge your day
as bare as salt
then, beached and scoured and spent, you sleep
clean as a naked shoot drawn to warmth
who, healing, stirs and breaks old webs
and pushes apart the soil that weighs your wear;
and, as a bird at birth
beats open its lid
fiercely pecking with strong and wanton beat and thrust
you know that you live
and bathe in water awake with tongues of light
and breezes that melt the steel of dark
you thank the day
and begin, while there is light
with steady practice
to learn and study stillwells to the sensitive skin
so seeing with eyes wiped free
your mortal like
as if transparent and clear
yet still opaque
you open your hand
shield a bowed head
raise straight a spine
secure a name
with direct eyes raise a face
exposed to yours
so heart springs, turning
aware and beating, alien, known
to your other and kind
as when light meets light
and you run like a child with tender soles
who remembers no hurt
on dunes and grass
nervous, laughing and ceremonious
choosing and steady as a homing bird
who climbs from sight
to soar like herons that take the sky in wide
deliberate wings and strong will
high, still, to rest
and peace and play.


Forever And Ever, the "Paradiso" of the cycle, is at once the most and least conventional of the three pieces. It is neatly divided into three movements (fast-slow-fast), yet each movement contains constantly shifting, subtly evolving musical textures; it starts by placing the violin in concerto-like juxtaposition to the chamber orchestra, yet ends by melding violin, orchestra and electronics into a single force; the hyperviolin music eschews the complex syncopated rhythms of the first two pieces, yet flows in an even more complex melodic line,

how bone freezes and ice cuts
and prove between dawn and dusk
how fire fusing with blood
which the player must project effortlessly despite tortuous rhythmic and technical challenges; the hyperviolin technology is the most advanced of the three pieces, yet is used to meld violin and electronics seamlessly, adding a special sheen and resonance to the violin sound, usually not sounding "electronic" at all.

In Forever And Ever, the kind of motion the music makes is also very distinct from the two earlier pieces. Begin Again Again... expresses a struggle to move forward and to break free, while Song Of Penance depicts a determined ascent from dark to light. Forever And Ever is gentler, more stable, yet constantly evolving, reflecting Dante's final words from the Divine Comedy (vv. 142-145, Ciardi translation):

        Here my powers rest from their high fantasy,
           but already I could feel my being turned -
           instinct and intellect balanced equally

        as in a wheel whose motion nothing jars -
        by the Love that moves the Sun and the other stars.

Machover writes: "Forever And Ever tries to convey the sense of a wheel turning and changing, yet of itself revolving in a kind of circle: like a person whose personality and circumstances continue to evolve and change while life's larger orbit has been glimpsed and accepted. In this 23-minute piece, the sinuous and cascading hyperviolin serves as a kind of musical guide, sometimes building up harmonies from its own sounds, at other times sending sparks of timbre splintering through the orchestra, and at yet other times creating layers of pulsating rhythms. Forever And Ever progresses from a sense of contented lyricism to a very calm and concentrated introspection, then moves through layer after layer of spinning and accelerating sound masses. The work ends in a joyful dance of affirmation and acceptance, and is dedicated to my wife, June Kinoshita."

Forever And Ever was commissioned by The Saint Paul Chamber Orchestra, through a grant from the Meet-the-Composer/Lila Acheson Wallace Fund. It was premiered by the orchestra in September 1993, with Ani Kavafian as soloist and Hugh Wolff conducting. Several improvements were made to the hyperviolin that make it slightly more sophisticated than the other two hyperstring instruments, including a wireless bow (developed by Neil Gershenfeld and Joe Paradiso) that dispenses with encumbering cables and adds sensitivity to the measurement of phrasing, and new techniques for interpreting subtle changes in the instrument's acoustic sound quality (developed by Eric M^Ntois and Eran Egozy), that make it easier for the hyperviolinist to control the computer extensions through delicate timbral variation. In fact, the soloist is probably most free in Forever And Ever to forget about the technology and just play, with the computer part following in a seemingly organic way.

Forever And Ever also represents a natural culmination and completion of the Hyperstring Trilogy. Many elements from the other two pieces are recapitulated and transformed, from the opening of Begin Again Again... which is echoed - very high and descending, rather than low and trying to ascend - at the beginning of the hyperviolin work, to the main hypercello themes which come back as a swirling pedal point in Forever And Ever's final ecstatic dance. Machover writes: "All that was tension and striving is now balanced and accepting, all that was dissonant is sunny and bright, all that seemed electronic and alien has been absorbed into a rich, natural, hyper-orchestral sonority. Yet the final held note of Forever and Ever, with its unusual resonance, leaves the listener not with a sense of complete closure, but with a gentle question mark, as if one were preparing not to 'begin again,' but certainly to continue..."