Between the Keys is an Ensemble Offspring project exploring new instruments and new tuning systems. The project is a reincarnation of our Partch’s Bastards project, first presented in 2011, finding inspiration in the music and ideas of maverick American composer Harry Partch.

On encountering the iconic Harry Partch you can’t help but wonder if the history of Western music took a wrong turn somewhere after Bach’s Well Tempered Clavier. Partch’s musical ideas were so revolutionary that they could not be performed on existing instruments and he had to design, build and perform an entire orchestra of novel instruments himself.

Although Partch died in 1974, his legacy continues to grow with a young generation of musicians around the world keen to expand his theories. Partch’s innovative vision and do-it yourself aesthetic resonates strongly with Ensemble Offspring’s artistic mission and in this project we pay tribute to this luminary in our own exploration of just-intonation and instrument building.

Between 2010-11, Ensemble Offspring commissioned the design of entirely unique wind and string instruments from the Australian master instrument builders Peter Biffin and Linsey Pollak as well as commissioning a number of composers to write works that exploit their characteristics. At the centre of this project is Kraig Grady, a Californian-come-Wollongong musician who traces a very direct legacy to the Partch tradition particularly via his connection to the alternative tuning theorist Erv Wilson. For this performance Grady has shared with Ensemble Offspring a unique tuning system – centaur tuning – on which all instrument builders, composers and performers have based their music. He has also constructed the centaur vibraphone featured in the recording as well as composing a new work for the project.

It hasn’t been easy recreating music completely from scratch: from newly invented tuning theories to the design of new instruments to play them, not to mention the task of composing for them and the challenge of learning how to play them. The project has involved an artistic team of instrument builders, composers and musicians working to common themes. Ensemble Offspring is very grateful to all those involved for their creative contribution to an imaginative new world of musical colour.

Equal & just temperament

In order to understand just-intonation and its relevance to this project, it is probably worth casting a critical eye over our ubiquitous system of equal temperament that most of us take for granted.

Equal temperament is where the twelve notes of the octave are evenly distributed. A semitone is a semitone regardless of where the interval is played. The system has proven useful for music that frequently modulates because the intervallic relationships between the notes are always the same regardless of the key in which the music is performed. The system is not without its problems, however. Most crucially, the consonance (or purity) of equal tempered intervals are compromised in order to force them into equal distances from one another. The interval of an equal tempered major third, for example, is quite audibly larger than the major third that occurs naturally as part of the harmonic series: the latter being more resonant or ‘in-tune’. Equal temperament has also been criticised for its harmonic blandness. By squaring-out and standardising the available tones to a limited number of intervals we miss out on a rich and nuanced vocabulary of harmonic possibility.

Just-intonation, by contrast, is any type of tuning system where the frequencies of the scale are built only out of whole number ratios (usually the lower intervals of the harmonic series). In tuning theory, these notes are often expressed as interval ratios in relation to a single fundamental tone: for example a 3:2 interval (the interval between the 2nd and 3rd harmonics) is equivalent to the musical interval of a perfect fifth. Harry Partch devised a just-intonation system that used all the intervals found in the harmonic series up to the 11th partial and by combining these intervals in a variety of ascending and descending patterns created a scale with 43 notes per octave. Even though the scale is very microtonal, the distance between each note is unequal. Partch’s 43-note octave formed the basis for the design of his unique ensemble of instruments.

Centaur tuning

With a conventional 12-notes per octave, a first glance at Kraig Grady’s centaur tuning may not seem a radical microtonal proposition, however there are several facets that make the temperament distinctive. The centaur tuning is a 7-limit just-intonation system, meaning that the scale incorporates the pure intervals of the harmonic series up to and including the 7th partial. Pitches derived from ratios incorporating 7 are noticeably at odds with the notes you may normally hear on a keyboard and as such immediately imbue Grady’s tuning with a striking ‘foreign’ quality. The notes of Grady’s scale are constructed by combining the intervals of 2 harmonic series based on C and F as well as a subharmonic series (a harmonic series flipped upsidedown) on A#. The variance in interval sizes between the notes is conspicuous and colourful: where an equal tempered system provides musicians with 12 possible musical intervals to work with, the same number of notes now provides 51 different intervallic combinations.

New instruments

Grady’s centaur tuning is most transparent on his centaur vibraphone, an instrument that is featured in many of these works. The instrument is a regular vibraphone whose keys have been cut, filed & drilled to adapt the tuning to his centaur scale. In addition to the centaur vibraphone, Grady has also provided a series of lower-pitched metal instruments, called Meru bars ,as well as a harmonium-like instrument whose reeds have also been adapted to play in the centaur tuning.

Instrument builder Linsey Pollak has a reputation for making and playing instruments made from rubber gloves, carrots, watering cans, chairs, brooms, bins, and other found objects. He has also designed more refined wind instruments and for Ensemble Offspring has crafted a set of clarinet-like instruments out of gidgee wood that he calls clarinis. In order to match the centaur tuning, the finger holes have had to be drilled in a precise and unconventional spacing. As an open-holed wind instrument, the clarinis face many limitations. Without a key mechanism, the size of the instrument has had to be restricted, providing only a limited range as well as a limited selection of notes. In fact it is not possible to play all 12 of Grady’s centaur pitches on a single instrument, hence 4 different clarini have been made, each of a different subset mode that only collectively can play all of the centaur notes.

Peter Biffin is one of Australia’s leading makers of string instruments. Of particular note are his tarhu, a family of spike-fiddles, an instrument similar to kamancheh found throughout the middle east and central Asia. The tarhus are characterised by a unique acoustic system where the vibrations of the strings are transferred into a wooden cone within the body of the instrument. The design provides the instruments with a responsive dynamic range as well as a sensitive variety of colour. Until now, all of Biffin’s designs have been for instruments that are held on or between the knees (gamba style) and this, the undachin tarhu is the first of his instruments to be held in a violin-like fashion. In addition to the unique method of tone-production, the undachin tarhu also includes a set of seven sympathetic strings under the fingerboard which can be tuned in a variety of ways to support different systems of temperament.

About the works

Arana Li | Mysteries
As with many of my works, Mysteries shows a preoccupation with the Chinese Ménglóng Shi Rén poets, specifically the work of Bei Dao. Much of my work has sought to capture similar quality of fertile ambiguity. Although not written for voice, I still vocalise fragments of Dao’s text as a means of generating melodic contour and phrasing. A rhythmically free work structured in four sections, Mysteries plays out as a multilayered dialogue oscillating between instruments (the earthy sound of the clarinis against the airy sound of the tarhu) and between two competing modes found within Grady’s colourful intonation. (AL)

Philip Glass | Music in Similar Motion
Music in Similar Motion is one of Philip Glass’ early minimalist works. Written in 1969 for the Philip Glass Ensemble, these early works tend to be far more austere than the expressive language he is noted for today. The title Music in Similar Motion describes exactly what happens in the piece: musical lines always move in the same melodic direction although not always in parallel intervals. The melodies are constructed as cells that are repeated ad lib until one of the musicians gives a small cue to move onto the next cell.
The constant repetitive and static nature of the harmony, colour, dynamics and tempo draws the listeners’ attention to what does change in the work: rhythm. Glass’ approach to rhythmic processes stemmed from an interest in Indian music. Instead of rhythms that emerge out of regular patterns of repeating accents, such as are found in European-derived classical and popular music, Glass builds his piece from short rhythmic units which are added to each other, as he says, “in western music we divide time, as you slice a loaf of bread. Indian music takes small units, or ‘beats’ and strings them together to make up larger time values.”
The diatonic palette and harmonic stasis make the work ideal for just-intonation interpretation. The most distinctive difference between this version and equal tempered versions is that the characteristic minor third that begins most of the melodic cells is significantly flattened (to a 7:6 interval) to provide an exotic but resonant quality. The absence of a pedal to dampen the notes of the centaur vibraphone contributes to resonance of a more reverberant kind creating a dizzying and glowing hypnotic mass. (DR)

Amanda Cole | Hydra
Hydra is a three-movement clarini duet exploring pentatonic subsets of Ancient Greek scales found in Kriag Grady’s ‘centaur’ just-intonation scale. Two of these scales are the Olympos’ pentatonic & Archytas’ enharmonic scales, which are used in Partch’s piece Two Studies on Ancient Greek Scales.
In Ancient Greek mythology, The Hydra of Lerna was a serpent-like water beast with multiple heads. In this piece, the clarinis act as individual parts of the one creature that interact with each other in different ways.
In Hydra, all four clarinis are used in different pairs for each movement and are tuned to separate modes (C major, C minor, C phrygian and C lydian). Not all notes of the centaur scale or Ancient Greek modes used in the piece are available on each instrument. This means that the notes of a melody or phrase often have to be shared between two instruments using the technique of hocket.

The melodic material in Hydra is made from variations of a bell ringing pattern, which consists of four notes that are permutated to create an eight bar pattern. In the first movement, the pattern is harmonised to form counterpoint. The second movement is more of a chase where an embellished monophonic version of the pattern is shared between the two players. In the third movement, a drone is placed under the pattern to form an accompaniment. (AC)

Damien Ricketson | Some Shade of Blue
Subtitled a ‘plainsong for undachin tarhu (plus halo)’, Some Shade of Blue is a slow song-like solo set over a resonant aura provided by the centaur vibraphone. The undachin tarhu is the only one of the new instruments not to be fixed in its temperament, however, in this work it is required to perform precisely in a 19-notes-per-octave extension of Grady’s scale proposed by Terumi Narushima. The seven sympathetic strings under the tarhu’s fingerboard are tuned to the new notes added to Grady’s scale to provide the instrument with a set of resonant sweet-spot frequencies while the remaining 12-notes of resonance are heard via the centaur vibraphone.
The metaphor of colour is associated with the evolving and growing palette of intervals heard as the work unfolds. The slow intense ascent of the melodic line shadows the violin solo in the final movement of the Quartet for the End of Time by Messiaen: a composer whose use of pitch is intrinsically tied up with colour (‘synesthetically’ so). The colour blue is often used to symbolise eternity, the end-point for Messiaen’s quartet. The colour is also used to describe the subtle flattening of notes in Jazz and Blues music. Although I do not seek to directly evoke such musical traditions, the idea of the “blue note” – a note of heightened expressive potential lying between the cracks of the piano – is of poignant relevance. The title is also a loose play on David Hume’s “Missing Shade of Blue”: a philosophical proposition concerning the capacity of the mind to project an idea without being exposed to the relevant sensory experience (Is it possible to imagine a shade of blue that you have never seen?). The question similarly can be applied to musical situations such as our perception of pitch and has been a point of contemplation for me reconciling my theoretical understanding of microtonal tuning theories with my perceptual experience of previously unheard notes and intervals. Blue also just happens to be the colour I associate with my daughter Francesca to whom this work is dedicated. (DR)

Kraig Grady | Akashic Torus
The title Akashic Torus refers first to the Akashic records, that library found in the ether that contains all knowledge. The Torus is a donut shaped structure that somehow is a common representational mapping in our mind of many multi-dimensional patterns. Along with the intonation employed we have a looking back but not to some ‘Golden Age’ that never was, but as a door to view what have been discarded as musical possibilities or even what have been spoiled. The piece centers solely on pentatonics, an interest resurrected by my contact with Lou Harrison, who I envision as the present caretaker of pentatonic scales in the previously mentioned library. It is not unlike the room he had in his house of similar purpose. Of much interest also is in the effect of long meters as a resistance to the short time thinking we all are subject to. Although the meter of this piece contracts or expands it remains centered on a meter of 101 beats, making each bar about 55.5 seconds long. The striking of a meru bar most often marks this meter, but not always so I advise not counting. The piece has only 11 bars to show, yet it makes the piece exactly 1111 beats long. (KG)

Terumi Narushima | Hidden Sidetracks
In my piece I have taken the unique timbres of each instrument to explore the melodic possibilities of the centaur scale. Unlike the 12 basic intervals of the equal-tempered chromatic scale, centaur provides 51 different-sized intervals from just 12 pitches. For example, the smallest interval found in a standard scale is the semitone which is given the value of 100 cents; in centaur, however, there are four different types of “semitones” ranging in size from 63 to 119 cents.
Often, people interested in tuning theory are quite obsessive about numbers in this way, but for me the main attraction is the various shades of colour and nuance offered by just-intonation tuning. Too much choice, however, can also be confusing so I have focused on various subsets within centaur, including pentatonic (five-note) scales, a special category of six-note scales called hexanies, as well as seven-note scales built from repeating tetrachords. On the path to understanding this tuning, I made several detours along the way but the secrets of centaur remain elusive. (TN)

Notes by Damien Ricketson © 2013