Sound Processing Techniques
Nearly every sound heard in Canticum Sphaerarum went through some type of analog tape proecessing to distance the listener's familiarity with the source material.
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It was decided early in the production process that all material in the piece should be recorded and processed ourselves. Every sonic element originates from a real-life instrument or other analog sound source, and due to the extensive use of vintage analog signal processing, all sounds heard in Canticum Sphaerarum could have been produced using technology available between 1969 and 1972.
Tape Looping
"Analogue tape technology has long captured my imagination, and in recent years I’ve become enthralled with various tape looping techniques. Looping seemed to be a fitting production element for Canticum Sphaerarum not only because of its sonic qualities but also for the analogy the medium has with the orbit of the planets."
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-Jacob Souders
Several tape looping techniques exist (several of which are explored in this article), but the technique most commonly employed in creating Canticum is known as “Sound on Sound” (or SOS) looping. This technique allows for multiple layers of sound to build up on a single tape loop, creating large ambient textures from the simplest of sources.
Tape Speed Techniques
Varispeed (short for "variable speed") refers to the pitch control functions of a tape recorder. By changing the speed at which a recording is played back, its perceived pitch will also change. Digital pitch shifting often leaves audible artifacts, especially when used in such extremes as in this piece, so it was decided that pitch shifting via analogue tape would yield the most desirable results.
As mentioned previously, changing the speed of tape playback also changes its pitch. When the playback speed is halved or doubled, the recording will sound an octave lower or higher, respectively. This phenomenon was creatively used to drastically alter the pitch, speed, and timbre of several sounds heard in Canticum Sphaerarum.
Tape Techniques by Planet
Mercury
Mercury's timbre was created from the layering of several clarinet recordings. While the instrument produces a beautiful, elegant sound, it ironically became rather difficult to process because of its sine-wave like purity. A tape chorusing effect was eventually decided upon, and was achieved through layering multiple recordings of the same pitch all affected using slight varispeed. The layering of these altered recordings produced a lush chorusing effect, as if multiple clarinets were playing simultaneously. The final step in making Mercury's signature sound was to perform an analog tape flange with the layered clarinets, giving the planet a vibrant texture rich with upper harmonics.
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Venus
The tenor saxophone seemed to be an appropriate choice to reflect the planet's visual beauty and languid nature. Processing the recordings through Sound on Sound tape looping transformed single saxophone notes into a warm, hazy sonic atmosphere.
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Mars
Historically represented in music through the heavy use of low strings, bombastic percussion and low brass (à la Holst's The Planets), we too decided to use the cello to represent Mars. We also wanted all of the terrestrial planets in Canticum Sphaerarum to reside in an upper register, so Mars's texture is derived from notes played high on the instrument. Sound on Sound looping turned individual pitches on the cello into the building blocks for an assertive melodic line.
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Jupiter
As the largest planet and being named after the king of the Roman gods, Jupiter needed to have a very regal sound to it, and the trombone was an appropriate choice. The sound of the acoustic trombone was mixed with a patch created on an ARP 2500 modular synthesizer to help disguise the source sound. The two voices of Jupiter's melody enter and exit the texture throughout the piece.
Saturn
Saturn's sonic timbre needed to be as stunning as the planet itself, and we found the answer through an unconventional instrument: the wine glass. The planets' sound is made of two layers: one for its body and one for its rings. The sounds for the bodily layer were created by recording several "singing" wine glasses (moving a finger around its lip) and then using the Varispeed on a 3M M79 tape machine to re-tune these recordings to our desired pitches. The powerful Varispeed control of the M79 allowed for the pitch of each wine glass to be dropped by multiple octaves with no unwanted artifacts, a result that cannot be achieved through digital processing. When layered together, these re-tuned wine glasses perfectly capture Saturn's cloudy appearance.
The psychedelic sound of the planet's rings was composed from the recording of a single wine glass hit, a technique borrowed from Hugh Le Caine's Dripsody. The pitch of the hit was re-tuned to a pentatonic scale using the Varispeed control on an Otari MX5050B-II tape machine, and then arranged to create an ascending melodic figure. The ascending scale was then recorded back onto tape at a slower speed, and re-captured at double speed, resulting in the scale sounding an octave higher and twice as fast. This process was repeated three more times until a large, upward sweeping scale was created. A copy of the scale in reverse was then spliced on, resulting in a multi-octave ascending and descending scale. And after running this wine glass scale through Sound on Sound looping, the result was an incredible crystalline texture that conjures images of the ice and rock particles that make up Saturn's rings.
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Uranus
Uranus rotates on a horizontal axis, and this anomaly is reflected through the use of several reversed sounds. Layers of bowed marimba and vibraphone hits were used as the source material, and recordings of individual notes, some reversed, were meticulously assembled and processed with heavy tape echo to create a haunting melody with unique percussive accents.
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Neptune
As the furthest planet away from the Sun, Neptune's presence in the Solar soundscape was to be simple, yet noticeable. A pipe organ was used for Neptune's sound and is the only planet to not have any tape processing applied to it.