ryan rapsys :: composer, producer, musician, filmmaker

Antiquichrome || Ryan Rapsys
Deep explorations into microsound electronic ambience.

The-Novus-Arcadia CD, a feature length compact disc by Ryan Rapsys – “Overall, [The-Novus-Arcadia's] an immensely enjoyable experience, and it could well become a piece of electronic art that may be a required listen in the near future.” – Muse’s Muse, 7/31/2007

While reading, you may want to hear music by the artists mentioned here, among other eclectic artists and musicians, for free: Live365 Radio: Erratik Music

The birth of electronic music (or electro-acoustic music, as it is sometimes called) in the last century has had an extremely large impact on the music world and will continue to for many more years. Many different types of electronic music have developed, giving composers many opportunities to express themselves aurally. Musique concretè, pure electronic music, algorithmic music, and live electronics and instruments are several of the main categories of electronic music. While a brief history, description, and background will be provided for each type electronic music, techniques and applications of concrète music and live electronics will naturally be the focus of this research paper. Musique concretè is music created by electronically manipulating natural, pre-recorded sounds in any number of ways, such as changing the speed, reversing the sound or overdubbing (Ernst, 3). The concept of live electronics, I believe, developed out of the desire to utilize the enormous variety of electronic sounds and timbres while still maintaining the feeling and emotion that can only be achieved with live performance. The last section of the research paper will discuss the wide variety of techniques that have developed in order to better serve electronic composers in their attempts to express themselves. In order to help the reader understand the concepts discussed, electronic works and examples written by the author have been made available for download and will be referenced where appropriate.

Types of Electronic Music

Musique Concrète

In Paris in 1948, Pierre Schaeffer (1910-1995) presented a concert of music he composed exclusively for tape. He called this new type of electronic music musique concrète. A year later, Schaeffer and another French composer, Pierre Henry (b. 1927) [Amazon.com] created the first center for tape composition at the Radiodiffusion-Télévision Française (R.T.F.) (Ernst, 3). These events may be considered the beginnings of what was to become musique concrète.

Between 1951 and 1954, a number of composers realized works at the R.T.F., including Pierre Boulez (b. 1925) Amazon.com] (Étude I sur un son, 1952; Étude II sur sept sons, 1952), Olivier Messiaen (1908-1992)[Amazon.com] (Timbres-Durées, 1952), Karlheinz Stockhausen (b. 1928) [Amazon.com], (Étude, 1952) and Darius Milhaud (1892-1974) [Amazon.com], (La Rivière endormie, 1954) (Russcol, 81-82) (hear music from all genres like this here: Live365 Radio: Erratik Music).

Another composer who also spent some time at the R.T.F. working on his work Déserts (for winds, percussion and tape)[Amazon.com] and who was anticipating this evolutionary step in music even before it occurred was Edgar Varèse (1883-1965) [Amazon.com]. The most important early concrète works came from this composer, who also was one of the first composers to mix live instrumental ensembles with pre-recorded electronic sounds (in his work Déserts). This idea will be discussed in detail in the later section on live electronic. His work Poème électronique [Amazon.com] was commissioned for the 1958 Brussels World’s Fair and premiered inside the Le Corbusier’s Philips Pavilion, played on four hundred loudspeakers. This work was revolutionary in its superior use of pre-recorded sound techniques and its extreme sense of dimension (because of the stereo-like effects achieved through the use of the four hundred loudspeakers) (Russcol, 82).

Among other composers who saw premieres of their works at that particular World’s Fair were Iannis Xenakis (1922-2001) [Amazon.com], Pierre Schaeffer, Pierre Henry [Amazon.com], and the two American electronic composers Otto Luening (1900-1996) [Amazon.com] and Vladimir Ussachevsky (1911-1990) [Amazon.com]. The “Audio-Visual Research Foundation of San Francisco” presented a program demonstrating the possibilities of combining musique concrète with other art forms. This program was one of the first to feature pieces similar to today’s multimedia works (Russcol, 83).

The author has written a number of musique concrète works, his most recent (at the time this paper was written), Agoraphobia is available here: [agoraphobia.mp3]. This work utilizes a number of pre-recorded sounds and concrète techniques. The feeling of agoraphobia (an abnormal fear of open or public places) is depicted aurally by complex textures of mostly recognizable pre-recorded sounds. Some of the source sounds that can be heard within the piece include applauding, crowd noises, coughing, a band warming up, clanging silverware, a radio tuning, and the composer’s family singing “Happy Birthday” to him completely out of tune on his 21st birthday. It is certainly easy to see the endless timbral and textural possibilities at the disposal of a composer utilizing concrète techniques.

Pure Electronic Music

Pure electronic sounds may be defined as sounds created purely with the use of electronic equipment, such as a computer. The first purely computer-generated sounds were heard in 1957 at the Bell Telephone Laboratories in Murray Hill, New Jersey. While studying telephone quality, Max V. Mathews (b. 1926) [Amazon.com] created a converter to put sound into a computer and converter to get it back out again. This lead to the development of Music I, a sound-generating computer program. It only had the capabilities to play back one voice in one waveform (a triangular wave)—it had no attack or decay. The only controllable parameters where pitch, loudness, and duration (Chadabe, Electric Sound, 108-10).

In the years to follow, a number of Music-N (as they were collectively called) sound-generating computer programs were developed, the last development in that line being CARL (Computer Audio Research Laboratory), developed in 1979 by F. Richard Moore (date of birth unknown). During non-peak hours (late at night), when fewer people were using CARL, it would take between ten and one hundred seconds to compute one second of sound. This meant that a composer working alone on the system could enter a composition of any level of complexity and hear it just minutes later being performed perfectly (Chadabe, Electric Sound, 122-123). Despite the many drawbacks—the technical knowledge needed, the lack of any sense of emotion, the disattachment of the composer from the music—computer-generated music remained appealing because of the ease it granted to experiment. Computers also gave composers (which were actually scientists in the early stages) the opportunity to compose sound itself (Chadabe, Electric Sound, 126-27).

In 1972, Charles Dodge (b. 1952) [Amazon.com] composed Speech Songs [Amazon.com, Downloads and More Info] by using an analysis-synthesis process for speech synthesis. He would read surrealistic texts, which were written by Mark Strand (b. 1934) [Amazon.com], into a tape recorder. Then he would input the audio into the computer through an analog-to-digital converter. The computer would then analyze the voice and resynthesize it. This technique, as well as several others that were later developed, allowed computers to generate vocal music (Chadabe, Electric Sound, 123-24).

The following audio files are two short examples of pure, computer-generated sound: [sine wave, white noise].

White noise may be defined as a sound created by combining sounds from every frequency. It may be compared to white light, which is created by combining all different colors of light. Combining sounds of a particular range of frequencies can generate different “colors” of sound. Noise, which is available for download here: [noise.mp3], is a work written by the author that uses that same, single, pure computer-generated sound as its source material: spatial stereo noise. Various colors (brown, white, or pink) of noise were generated, and then they were manipulated electronically (utilizing many of the same techniques commonly used in musique concrète). This work–entitled such because of the source sounds, of course–is a good example of how computer-generated sounds can be used to create unique sonic landscapes.

Algorithmic Music

Automation has been explored and applied to music for hundreds of years. Salomon de Caus (1576-1626) [Amazon.com]described a type of organ powered by a water wheel in France in the first half of the 17th century. The water wheel turned a pegged cylinder which activated levers which triggered bellows to force air through certain pipes (similar to a large music box). This type of automation in music began to really take hold in the 18th and 19th centuries, with many water organs, music boxes, musical clocks, and barrel organs being made. Today, with the aid of computers, a lot of music has been composed using automation, including music with pre-determined results (like earlier musical automata) and results based more on chance and chaos theories (Chadabe, Electric Sound, 268-69).

Iannis Xenakis [Amazon.com], one of the most admired avant-garde composers of all time, was heavily influenced by the brutal experiences of his younger years, particularly when he was studying engineering in Athens during World War II. After hearing a shouting crowd shot at by machine guns on Constitution Square in Greece, thousands of screams, and then the strange silence afterwards, he “was left wondering what kind of music could ever express the totality of those changes in sound.” Whenever he spoke of these experiences, he always described the sounds of the events rather the than the sights. As far as algorithmic music (both electronic and acoustic), Xenakis is probably the most notable composer, as well as his work with orchestral music and musique concrète. Besides an excellent composer, Xenakis was also a mathematician, architect (he helped Le Corbusier design the Philips Pavilion for the Brussels World Fair, which played Varèse’s [Amazon.com] Poème électronique [Amazon.com]), and computer programmer (Russcol, 154-55). (hear music by Xenakis and others here: Live365 Radio: Erratik Music)

Due to a large amount of ambiguity with the definition of “algorithmic composition” (which is what computer-automated composition came to be called), it is important to clarify exactly what it constitutes. Algorithmic processes may either define 1) score material only (pitch, duration, dynamic material, etc., whether it is for electronic instruments/sounds, acoustic instruments, or both) or 2) both the score material and the electronic sound synthesis. If the processes only determine score material, the composer realizes the work electronically or by orchestrating it for live instruments. An example of this would be Xenakis’s Achorripsis [More Info] for orchestra, in which the elements of timbre, pitch, dynamics, and duration were determined by a Poisson distribution [More Info].

This type of algorithmic music was termed stochastic music by Xenakis, which can be described as music based on the laws of probabilities and the laws of large numbers. After the data to compose the piece was gathered, Xenakis translated it and orchestrated it. Therefore, it is important to note that algorithmic music is not necessarily always electronic (Chadabe, Electric Sound, 279-80, 284).

The following audio sample is a short algorithmic work composed by the author that plays back a randomly generated twelve-tone row, its retrograde, its inversion, and finally its retrograde inversion: [twelve tone].

It is a very simple work designed to demonstrate the concept of algorithmic music. The durations of each tone are also generated randomly and undergo the same mutations as the pitches. This piece was “composed” by writing the criteria of the work in the Basic programming language. This would be considered an algorithmic work in which both the score material and the electronic sound synthesis are determined and created/performed by the computer (in this case, the timbre is that of the generic sine tone generation of the computer’s internal speaker). Every time the program is run, the order of the tones and the durations are randomly generated. The audio sample contains one particular output generated by the program.

Live Electronics and Instruments

Almost as soon as electronic sounds were being used regularly in composition, ways to somehow unite these new timbres and textures with the flexibility and emotion of live performance were being explored. This has been achieved with considerable success in primarily three ways: 1) creation of an electronic instrument, 2) having live performers play along with a tape of electronic sounds, or 3) by having the output of the instrument itself be electronically manipulated in real-time (Appleton, 287).

Probably the earliest electronic instrument created was an electromagnetic resonator controlled by a vibrating metal bar and a hammer, patented in 1885 by Ernst Lorenz (dates unknown) (Appleton, 287). However, by far the most popular and well-known early electronic instrument is the aetherphone, or what later came to be known as the theremin. This instrument was invented by the Russian Leon Theremin (1896-1993) [Amazon.com] and was first demonstrated by him in Moscow in 1920. It was a cabinet approximately one foot deep, eighteen inches wide, and about two feet high. A pitch antenna branches up from the right side of the box, while a looped volume antenna protrudes from the left side. The closer the right hand is to the pitch antenna the pitch goes up. The closer the left hand is to the volume antenna the pitch gets softer. It did not take long for Theremin to become a celebrity, having performed in Frankfurt, Berlin, London, Paris, and New York by the end of the decade (Chadabe, Electric Sound, 8). Today, the theremin is still performed worldwide in its updated form (Appleton, 289).

By 1950 many patents for electrical music devices had been issued, most of them designed to be performed live (Appleton, 287). One other instrument to note, the Ondes Martenot [More Info], became attractive enough to a number of composers, including Edgar Varèse [Amazon.com], Olivier Messiaen [Amazon.com], Paul Hindemith (1895-1963) [Amazon.com], and Darius Mihaud [Amazon.com], that it actually has a fair amount of original music for it. This instrument was controlled by pulling a ribbon left or right to control pitch and manipulating controls on a small panel to control volume and timbre (Appleton, 290).

The reason these instruments, which were forms of immediate communication of musical information, developed far more quickly and far before other forms of electronic music is primarily because of various social, economic, and technological reasons. For these same reasons, the telegraph and telephone (again, forms of immediate communication of information) developed much more quickly then magnetic recordings (which is a form of delayed communication of information). However, after further development of the magnetic tape recorder during World War II by the Germans, it finally came into more common use, allowing for the early experiments of Pierre Schaeffer and Pierre Henry [Amazon.com]. Simultaneously as these early musique concrète experiments were being carried about, composers were finding ways to conjoin them with live instruments performed by live musicians (Appleton, 287).

For several reasons, composers sought ways to combine recorded electronic sounds with live performers. First of all, just playing back a tape in a concert hall for a performance had a number of obvious drawbacks, especially because of the traditional mindset of the typical concert audience. Secondly, many composers who began to work with tape still continued to compose for traditional instruments as well. They naturally found themselves developing ways to combine both ideas. As mentioned before, Edgar Varèse [Amazon.com]. was one of the first composers to create a work which utilizes both musique concrète textures and timbres as well as live performers playing more traditional instruments. His work Déserts [Amazon.com] has sections where just the live performers are playing and sections where just the tape with concrète sounds are playing. The sounds on the tape often had many different sources, sometimes acoustic and sometimes electronic (Appleton, 292-93). The many techniques developed in order to somehow synchronize and create coherence between the electronic sounds and live performers will be discussed in detail in the section on the applications and techniques of live electronics. Imaginary Landscapes [Amazon.com] by John Cage (1912-1992) [Amazon.com]. is one of the earliest works to use electronic amplification during live performance to bring out sounds that would otherwise be unheard (Appleton, 295). This work, which premiered in 1939, also called for variable-speed phonograph turntables (Chadabe, Electric Sound, 25-26). Further developments along these lines occurred, creating the concept of real-time electronic manipulation of acoustic sounds as they are performed. Various devices would be set up in between the microphone and the speakers, such as ringmodulators, that would manipulate the sound in one way or another.

One example of this type of electronic music is the piece Mantra [Amazon.com] by the German composer Karlheinz Stockhausen [Amazon.com]. It is written for two amplified pianos, the output of which is run through ringmodulators. The effect is similar to that of John Cage’s prepared piano works except that the preparation is electronic instead of concrete. At different points, the pitches of the piano are manipulated in different ways as they are performed, thus utilizing electronic timbres while maintaining the feeling of a live performance (Stockhausen, Mantra, from liner notes by Reinhard Oehlschlägel). (hear music by Stockhausen and others here: Live365 Radio: Erratik Music)

Techniques and Applications of Musique Concrète

Since the late 1940s, musique concrète techniques can be heard in nearly every imaginable style of music. Because of this, a wide variety of concrète compositional techniques have been developed in order to better serve composers working in these different styles. These different techniques have been applied in many ways in order to serve some sort of artistic expression.

Techniques

The most commonly used, as well as easiest to hear, concrète techniques include reversing, speeding up and slowing down. Sample one contains a short sound of a marimba being struck with a twenty ounce pop bottle. Sample two contains the same sound reversed. Sample three contains the same sound stretched by 200%. Sample four contains the same sound compressed by 50%. Sample five contains a complex texture created using the same source material. Several variations of the texture were created using the different techniques, and then the variations were mixed together spatially (some variations sounding more from the left speaker, others from the right). Of course, these examples only demonstrate a couple of the more simple manipulative techniques available to the concrète composer: [pop bottle marimba (normal), pop bottle marimba (reverse), pop bottle marimba (stretched), pop bottle marimba (compressed), combinatory texture].

Today, computer audio editing programs give composers the ability to apply many manipulative processes on any particular source sound. Another concrète work by the author, entitled Scissors is available for download here: [scissors.mp3]. This work demonstrates how incredibly powerful concrète techniques can be for creating new sounds. For the source material, the composer recorded the snipping of a pair of scissors. By using a large variety of techniques, ten different “instruments” were created from that one source sound and then loaded into a sequencer. The music was then composed in the sequencer, which allowed the composer to create music with a rhythmic characteristic. In listening to this example, it is easy to hear how utilizing the many manipulative techniques at the disposal of a concrète composer can create an incredibly wide range of sounds.

Applications

Concrète techniques were first heard in rock music in 1957. David Seville (1919-1972, born Ross Bagdasarian) and the Chipmunks [Amazon.com] used tape transpositions to create high-pitched, cartoon-like vocals. The Beach Boys [Amazon.com] used a theremin, tape transformations and recording studio techniques in their songs “Good Vibrations” (1966) and “She’s Goin’ Bald” (1967). However, the Beatles’ [Amazon.com] Sergeant Pepper’s Lonely Hearts Club Band (released in 1967) [Amazon.com], which used such concrète techniques as tape reversal and transposition, loops, and meticulous splicing, really marks the beginning of consistent use of concrète techniques in popular music (Ernst, 132). Since then, two major genres of popular music that use concrète and other electronic music techniques nearly exclusively have been developed: rap and techno music.

One composer used concrète techniques to create a piece that has had an incredible influence on the music world. Premiered in 1965, It’s Gonna Rain [Amazon.com] by Steve Reich (b. 1936) [Amazon.com] uses a tape loop technique that actually developed out of an accident. Reich recorded the voice of a young black Pentecostal preacher as well as some pigeon and traffic sounds one afternoon in San Francisco. While working with the tapes, he accidentally discovered the process of phasing, which is playing back two identical tape loops at the same time, gradually changing the speed of one of the loops so that it phases out of sync with the other. A tape loop is created by splicing the loose ends of a section of tape of any length together into a loop. When played back, the tape will just continually loop the same section of audio, repeating it over and over (Ernst, 9). Reich then created a work based on the process he stumbled upon. The words, “it’s gonna rain,” as stated by the preacher, are repeated. Gradually one of the loops shifts speed, creating the phasing effect. This continues until the loops line up again. This is the basis of the work, which eventually contains eight voices (Chadabe, Electric Sound, 77). This and Reich’s other early tape loop pieces, such as Come Out, eventually lead to the development of the popular music genre of techno music (see the writing Intelligent Dance Music: Music for the Head). (hear music by Reich and the later electronica artists he influenced here: Live365 Radio: Erratik Music)

John Cage [Amazon.com] has applied concrète techniques in a variety of different and creative ways in many of his works. In 1951, John Cage and David Tudor (1926-1996) [Amazon.com] initiated the Project for Magnetic Tape in New York. Their first project was entitled Williams Mix [Amazon.com], which was titled such because their friend Paul Williams (1894-1980) gave them a portion of money in support of the project. Louis (d. 1989) and Bebe Barron (b. 1927), who had begun experimenting with taped sounds and simple electronic circuits as early as 1948 in New York, recorded approximately 600 sounds for the project. They were then catalogued in different categories, and then further categorized according to control or predictability, lack of control or unpredictability and pitch, timbre and loudness. Cage then created a score for the piece by flipping coins according to a procedure from the I Ching, which is an ancient Chinese system of divination. At this point, Earle Brown (b. 1926) [Amazon.com] began to help with the project, primarily helping with the long, meticulous process of cutting and splicing the small clips according to the score (Chadabe, Electric Sound, 54-57).

These are only several examples of how musique concrète techniques may be used in order to better serve a composer’s individual artistic expression. Of course, these techniques have also been applied to more traditional structures. Edgar Varèse’s [Amazon.com] Poème électronique [Amazon.com]), organizes the electronic sounds in a more traditional manner to create a unique expression. The author’s work Agoraphobia (available for download here: [agoraphobia.mp3]) also applies more traditional orchestrational and structural techniques to complex electronic textures. Clearly, these techniques may be satisfactorily applied to any style of music, thus opening up music to any and all sounds.

Techniques and Applications of Live Electronics

Using pre-recorded sounds in any work often creates a type of rigidity not often desired. Many composers have therefore developed techniques which combine concrète sounds with a live performance element, thus creating a more acceptable and valid concert hall experience. These techniques have been applied in a wide variety of styles in order to better accommodate a particular composer’s artistic vision.

Techniques

One way in which composers have been able to successfully combine electronic sounds with live performers is to graphically notate the electronic sounds so as to allow the performer to follow the score and play along with them as they occur. The author has written a work, entitled Fantasy for Piano and Electronic Sounds, which uses this technique. The pianist just listens for the cues on the CD, which are graphically represented in the score, in order to synchronize him/herself with the CD. The following audio sample contains the electronic sounds intended to accompany the piano for the same section shown in the score excerpt: [fantasy excerpt].

This is a score excerpt from the author’s piece Fantasy for Piano and Electronic Sounds.

Supplication, written by the author for ten percussionists and electronic sounds, uses another technique in order to synchronize live performers with pre-recorded sounds. A conductor watching the timer on the CD player signals the ensemble at the given indications. In between each signal, the performers are to improvise as indicated in their parts. The timer indications (5:44, 5:52, etc.) in the score specify when the conductor is to signal the ensemble to move to the next “measure.” To demonstrate, the following audio sample contains the electronic sounds to accompany the ensemble for the same section shown in the score excerpt: [supplication excerpt]. (hear electroacoustic music by Ryan Rapsys and others here: Live365 Radio: Erratik Music)

This is a score excerpt from the author’s piece Supplication.

These techniques demonstrate two of the more common methods of synchronizing pre-recorded sounds with live performers. Of course, a variety of other sophisticated techniques have been developed in order to accommodate many different composers’ particular styles.

Applications

In 1970, Mario Davidovsky (b. 1934) [Amazon.com] premiered Synchronisms #6 for piano and tape [Amazon.com], for which he won a Pulitzer Prize in 1971. His idea with the piece primarily dealt with, as stated by him, “stretching an instrument by adding electronic sounds and stretching electronic sounds by having a performer capable of the nuance and phrasing that the tape didn’t have at the time.” He was able to do this by notating graphically in the piano score the electronic sounds heard on the tape. By having a live performer on the stage, he was able to present electronic sounds in a way that would be acceptable to a concert hall audience (Chadabe, Electric Sound, 69).

The premiere of Steve Reich’s [Amazon.com] piece City Life [Amazon.com], which uses yet another method of combining a live performance element with pre-recorded sounds, occurred in 1995. Pre-recorded samples of speech, car horns, door slams, air brakes, subway chimes, pile drivers, car alarms, heartbeats, boat horns, buoys, and fire and police sirens are loaded into two sampling keyboards, which are then performed by two keyboardists. The work is written for an ensemble including two flutes, two oboes, two clarinets, two pianos, two samplers, three (or four) percussion, string quartet, and bass. By having the electronic sounds loaded into a sampling keyboard and played by live performers, Reich is able to maintain the flexibility of tempo, allowing for a performance more acceptable for the concert hall (Reich, from liner notes).

In 1965, Music for Solo Performer by Alvin Lucier (b. 1931) [Amazon.com] was premiered. Lucier creates a live performance atmosphere in an incredibly creative way. In the piece the solo performer’s alpha brain waves are transmitted to amplifiers and loudspeakers and then directed at various percussion instruments placed around the concert hall, causing them to reverberate. In this case the electronic sounds serve as a catalyst in the creation of acoustic sounds in a performance space. Therefore, Lucier successfully combines technology with a live performance element, thus creating music acceptable to be presented in a concert hall setting (Chadabe, Electric Sound, 96-97).

Conclusion

The desire for composers to use pre-recorded or other electronic sounds has and will continue to be strong. New technology has always opened up music to a wider range of sounds. John Cage [Amazon.com] has spoken quite often on his philosophy of “everything is music.” Pre-recorded and other electronic sounds easily allow for exactly that. Finally, music can be opened up to include any and all sounds.

Bibliography

Appleton, Jon H. and Ronald C. Perera, eds. The Development and Practice of Electronic Music [Amazon.com]. Englewood Cliffs, New Jersey: Prentice Hall, 1975.

Chadabe, Joel. Electric Sound: The Past and Promise of Electronic Music [Amazon.com]. New Jersey: Prentice Hall, 1997.

Chadabe, Joel. “The Electronic Century Part III: Computers and Analog Synthesizers.” Electronic Musician [Electronicmusician.com] 15 (2000): 86-98.

Chadabe, Joel. “The Electronic Century Part IV: The Seeds of the Future.” Electronic Musician [Electronicmusician.com] 16 (2000): 36-50.

Emmerson, Simon and Denis Smalley. “Electro-acoustic music.” The New Grove Dictionary of Music and Musicians [Grovemusic.com], edited by Stanley Sadie and John Tyrell. 29 vols. London: Macmillan, 2001. 8: 59-67.

Ernst, David. The Evolution of Electronic Music [Amazon.com]. New York: Schirmer, 1977.

Reich, Steve [Amazon.com]. Proverb, Nagoya Marimbas, City Life [Amazon.com]. (CD). New York: Nonesuch Records [Nonsuch.com]. 1996. 79430-2.

Russcol, Herbert. The Liberation of Sound: An Introduction to Electronic Music [Amazon.com]. Englewood Cliffs, New Jersey: Prentice Hall, 1972.

Stockhausen, Karlheinz [Amazon.com]. Mantra [Amazon.com]. (CD). San Fransisco: New Albion Records [Newalbion.com]. 1990. NA025.

Ussachevsky, Vladimir [Amazon.com], Otto Luening [Amazon.com], Bulent Arel [Amazon.com], Mario Davidovsky [Amazon.com], Pril Smiley [Amazon.com], and Alice Shields [Amazon.com]. Pioneers of Electronic Music [Amazon.com]. (CD). New York: Composers Recordings, Inc. [Composersrecordings.com] 1991. CD 611.