Carrillo piano

A remarkable 96-tone piano

The Carrillo piano, also referred to as the 96-tone piano (or officially the 1/16-tone piano), is an exceptional musical instrument offering extensive microtonal possibilities. Developed in the 1950s by the Mexican composer Julián Carrillo (1875–1965) in collaboration with the German piano builder Carl Sauter, this piano has inspired countless composers and musicians to explore new musical avenues. Today, this rare instrument is held by institutions such as the Conservatoire National Supérieur de Musique et de Danse in Paris and the Huygens-Fokker Foundation at the Muziekgebouw aan ‘t IJ in Amsterdam.

The Sauter Carrillo piano is tuned in 96-tone equal temperament, which divides the octave into 96 equal steps. This means the interval between two adjacent keys is a 1/16-tone, or just 12.5 cents. Sixteen keys are required to span a whole tone (for example, from C’ to D’), and eight keys for a semitone (such as G’ to G♯’). The keyboard contains 97 keys and 291 steel strings. The Carrillo piano stands 116 centimetres tall and visually resembles a standard upright piano but covers only one octave in pitch range, from C1 (middle C) to C2. Its visual octave span, however, extends over eight octaves, which may be potentially confusing for performers.
The Carrillo piano is a vertical instrument with a mechanism similar to that of a traditional piano. It is fully triple-strung and has two pedals: a sustain pedal and a soft pedal. Unlike a traditional piano, the soft pedal does not alter the tone colour but merely shortens the distance between the hammers and the strings (see brochure). In contrast to some other Carrillo pianos, the instrument at the Huygens-Fokker Foundation lacks a third (moderator) pedal but has a manual moderator, allowing a layer of felt to be placed between the hammers and strings to produce a muted, mysterious sound.

Within the 96-tone system of the Carrillo piano, which enables 16th-tone playing, various other tuning systems are also embedded, including the conventional 12-tone system, the 24-tone system (quarter tones), and the 48-tone system (eighth tones). It can also be played according to just intonation. Despite the 96-tone Carrillo piano and the 31-tone Fokker organ being based on two different (almost incompatible) systems, the instruments can sound remarkably in tune together, as the tones deviate by no more than 6.25 cents in the worst case. Due to their very different timbres, this slight difference is virtually imperceptible. Most notes on the Fokker organ thus have an almost perfectly corresponding note on the Carrillo piano.
Only when constructing consonant chords must occasional compromises be made, causing a particular note to deviate slightly more than 6.25 cents from the 31-tone organ. However, in most compositions for the 96-tone piano, only consonant intervals (two notes simultaneously) are played, since the large distances on the keyboard require four hands for full harmonic chords. A single performer can therefore play only intervals or micro-clusters on the Carrillo piano. (Check here for a chart showing the corresponding pitches between the Carrillo piano and the Fokker organ.)

To notate music for, among others, the 96-tone piano, Carrillo developed, in addition to a system of small marks placed before the notes, a numerical notation by simply assigning every pitch within the octave a number from 1 to 96. However, this proved difficult for performers to read. Today, scores are generally written in standard piano notation (usually over two staves), as if the pitch range extends from CCC to c5. Although the notation contains extreme leaps (all intervals on the keyboard are eight times larger than normal), in principle, any pianist specialised in contemporary music can read the score directly without learning a complex new system. The same applies to the piano keyboard itself, which is identical to a traditional piano but has 97 keys instead of 88. Carrillo anticipated the advantages of a conventional keyboard from the outset, as creating a specially designed keyboard for 96-tone music would have been impossible. In this way, the remarkable Carrillo piano ultimately became a practical instrument with readable sheet music.

The Carrillo piano distinguishes itself from traditional pianos by its unique character. Firstly, it produces a highly recognisable percussive sound, almost like a prepared piano, due to the absence of low notes, which prevents certain overtones from sounding. Whereas standard pianos use semitones as the smallest interval, this piano explores the subtle nuances between these notes. Carrillo’s refined 96-tone system can, in fact, approximate any interval or chord with remarkable accuracy. On the Carrillo piano, spectral chords can be performed to produce a wide variety of overtone sounds almost perfectly.
Furthermore, due to the small distances between keys, the instrument can be combined effectively with instruments tuned in other systems for polymicrotonal music (‘multiple division music’). Its derivation from the 12-tone system also allows it to be easily tuned and played together with conventional pianos, enhancing performance possibilities. Additionally, the extremely small pitch increments enable nearly any tuning of non-Western instruments to be reproduced on this extraordinary piano, which, unlike many other microtonal instruments, can be played by any pianist. This presents new challenges for both composers and performers and opens avenues for experimental music. With its innovative design and fascinating sounds, the 96-tone Carrillo piano has played a significant role in the history of microtonal music.

History of the Carrillo piano

The Carrillo piano, an instrument that pushes the boundaries of traditional music, is closely associated with the Mexican composer and music theorist Julián Carrillo (1875–1965). Carrillo, a pioneer of microtonal music, developed a revolutionary theory called Sonido 13, in which he proposed that music could evolve further through the use of intervals smaller than a semitone. His work inspired the creation of new instruments, including the famous 96-tone piano (or 1/16-tone piano), which represents a significant milestone in the history of microtonal music and a revolutionary step in the understanding and performance of pitches beyond the traditional Western scale.

Julián Carrillo was born in Ahualulco, Mexico. He began his musical education in a church choir and later studied violin, composition, and music theory at the Conservatory of Mexico City. During his studies, he became fascinated by the physics of music. In 1895, through experiments with a violin string, he discovered that he could divide a whole tone into sixteen equal parts. This formed the basis of his microtonal theory. In 1925, he devised his own notation for these ideas. After further studies in Europe, including at the Conservatory of Leipzig and the Royal Conservatory of Ghent, where he excelled as a violinist and composer and laid the foundation for his later innovations, Carrillo returned to Mexico. He became an influential figure in Mexican musical life, working as a conductor and teacher, and introduced a new musical direction with his Sonido 13 theory (“The Thirteenth Tone,” which essentially represented the first tone beyond the conventional twelve), through which he introduced microtonal intervals smaller than a semitone. He created new compositions, founded ensembles, and designed innovative instruments to make microtonal music possible. In 1950, Julián Carrillo was nominated for the Nobel Prize in Physics, though he did not win.
However, his work often clashed with traditional musical conventions, encountering resistance both in Mexico and internationally. Despite Carrillo’s artistic genius and support from prominent figures such as Leopold Stokowski, with whom he founded an ‘Orquesta Sonido 13’ and toured during the 1930s, his work was regularly criticised and marginalised. Nevertheless, Carrillo continued to experiment tirelessly with microtonal systems and collaborated with instrument makers to realise his revolutionary ideas, including the 96-tone piano, as well as customised harps and string instruments. Throughout, he remained true to his own vision, resulting in a body of work that is both experimental and deeply rooted in traditional structures.

In the 1940s, Carrillo designed and patented fifteen so-called metamorphoser pianos, each tuned to a specific microtonal system, ranging from whole tones, quarter tones, to 1/16-tone intervals, and all divisions in between. The 96-tone piano is among the most remarkable of these instruments. With ninety-six keys per octave and intervals of only 12.5 cents between adjacent keys, the instrument opens an entirely new and highly detailed sonic universe. The pianos, built by the Carl Sauter factory in Spaichingen, were first presented at the Brussels World’s Fair in 1958, where they were awarded a médaille d’or (gold medal). Three of these instruments are now held at the Conservatoire de Paris (two in sixteenth-tone and one in third-tone), while others are located in conservatories in Nice, Mexico City, Freiburg, and Vancouver. Later models of the 96-tone piano can be found in cities such as Buenos Aires, Montréal, Lisbon, and at the Hochschule der Künste in Bern.
Carrillo’s microtonal instruments, including the 96-tone piano, have influenced many composers worldwide, including György Ligeti and Giacinto Scelsi, who built on Carrillo’s ideas, though often from different aesthetic perspectives. His work also resonated with other microtonal pioneers such as Ivan Wyschnegradsky and Alois Hába, who likewise developed new systems and instruments for quarter tones and sixth tones, respectively. Furthermore, his work inspired composers and researchers to continue experimenting with microtonal music. The 96-tone piano, a symbol of Carrillo’s vision and perseverance, continues to present new musical challenges for both performers and composers. Although Carrillo received both praise and criticism during his lifetime, his contributions have proven invaluable. His work challenges conventional musical boundaries and emphasises the potential of microtonality to explore new musical worlds. (Read more about Julián Carrillo in the online archive of the Huygens-Fokker Foundation)

Between 1997 and 2000, the original German piano maker Sauter produced a new series of ten Mikroton 1/16 pianos, which have been referred to as Carrillo pianos by the Huygens-Fokker Foundation since 2010. One of these rare, difficult-to-sell, and particularly expensive instruments reached the early 21st century, through the good contacts of Robbert Westera with Sauter, at the piano dealership Westera in Winterswijk. From this location, work began on the possible performance of the instrument in the Netherlands, which among other things resulted in an initial collaboration with the Huygens-Fokker Foundation. 

On 5, 6, and 7 August 2005, as part of the Hortus Festival organised by saxophonist and festival director William Raaijman (and with financial support from the foundation), a series of concerts took place in Utrecht, Leiden, and Amsterdam, featuring among other instruments the Carrillo piano, played by pianist Maarten van Veen, who had encountered the instrument in Winterswijk in 2004.
In 2008, the Huygens-Fokker Foundation, now under the leadership of artistic director Sander Germanus, contacted the firm Westera in a first attempt to acquire this remarkable 96-tone piano. However, it was not until early 2011 that the instrument—approved by Sauter, with additional sponsorship from the importer, a substantial donation from the Netherlands Acoustical Society (originally co-founded by Professor Adriaan Fokker), and support from six well-known consulting engineering firms—was definitively acquired by the Huygens-Fokker Foundation.
The first concert with the Carrillo piano, entitled Carrillo vs Fokker, took place later that same year, on 16 October 2011, in the Kleine Zaal of the Muziekgebouw aan ‘t IJ, performed by organist Ere Lievonen on the Fokker organ and again by Maarten van Veen on the Carrillo piano. Following this successful performance, multiple Fokker organ concerts have been organised annually, in which the 96-tone piano played a musical role, and a repertoire has emerged for both the 96-tone piano solo and in combination with the 31-tone organ. In 2013, the Carrillo piano also became part of Ensemble SCALA, the microtonal house ensemble of the Huygens-Fokker Foundation. In this context, the instrument is played by pianist Anne Veinberg, who has since specialised in the instrument. In 2021, a long-cherished wish was realised when the Carrillo piano was equipped with a manual moderator by Sauter, allowing the sound to be made significantly softer. With all these capabilities, the 96-tone piano has proven to be a sublime addition and will remain of great musical value to the Huygens-Fokker Foundation for the Fokker organ concert series and beyond.