A Young but Rich Field of Innovation

The quarter-tone accordion is a recent development. Although the accordion has existed for nearly two centuries, the systematic inclusion of microtonality—via full 24-EDO keyboards or partial quarter-tone modifications—has accelerated since the early 2000s. In just a few decades, a striking array of systems has appeared, each reimagining how microtonality can be integrated into the instrument. 1)

Instruments Adapted for Arabic Maqām: The “Accordion Oriental”

In early 20th-century Egypt, accordion makers responded to the requirements of the maqām system by modifying specific reeds to quarter-flat pitches, such as E-half-flat or B-half-flat. These alterations were activated through dedicated registers or implemented in bisonoric controls, where push/pull produced different pitch responses. Marketed as “accordion oriental” (accordéon oriental, Arabic: الأكورديون المعدَّل لإنتاج أرباع الصوت), these instruments enabled the accordion to blend authentically into maqām ensembles—without a full microtonal layout redesign. 2)

Veli Kujala: Isomorphic 24-EDO System (2005–2006)

In 2005, Finnish accordionist Veli Kujala, together with composer Sampo Haapamäki, designed a fully microtonal system based on interchangeable reed blocks. In 2006, Pigini Accordions built the additional reed blocks, which Tapio Peltola tuned in September of that year. 3)

  • Right manual: fully tuned to 24-equal temperament (24-EDO) across all stops.
  • Left manual: the lowest two octaves of the 8′ and 4′ stops remain semitone-tuned; the upper ranges are quarter-tone. The 2′ stop remains semitone-tuned. These limitations are due to the glued construction of the lowest reed blocks and the impracticality of fitting a 2′ quarter-tone stop. 4)
  • Keyboard design: preserves the isomorphic button layout, with doubled intervallic spans: fingering patterns transpose, but intervals differ from 12-EDO logic.
  • Technical build: integrated into a Pigini Sirius body, featuring eight reed blocks (six on the right manual, two on the left). With quarter-tone steps on the right hand, the instrument trades octave span for pitch resolution (≈ half the range of a 12-EDO system). 4)
  • Context: developed as part of Kujala’s doctoral research at the Sibelius Academy.

Since its creation, Kujala has premiered multiple works on this system—including Haapamäki’s concerto Velinikka (2008), the initial impetus for the instrument. 3)

First recording featuring Kujala’s quarter-tone accordion is Kalle Kalima & K-18: Some Kubricks of Blood, where only non cassotto reed blocks of the right manual are replaced with quarter-tone reed blocks.

This system represents a dedicated quarter-tone accordion.

Bjarke Mogensen has almost identical instrument with only small differences in tone range. He has premiered many works including most notably Sune Kølster’s Concerto for Quartertone Accordion and Orchestra.

Iñaki Alberdi has a similar system with interchangeable quarter-tone reed blocks for the right manual with slightly different tone range as Kujala’s system. Alberdi has premiered and recorded many works from composers such as José María Sánchez-Verdú and Zuriñe F. Gerenabarrena. Also Maria Zubimendi is using the Alberdi system. Many compositions written for them are notated in scordatura notation for making it quicker for performers to learn.

Wieslaw Ochwat has a similar system with with interchangeable quarter-tone reed blocks for the right manual with slightly different tone range as Kujala’s system. Some works composed for him such as Piotr Pezat’s Jenny’s soul (2017) are based on replacing only two stops with quarter-tones similarly to Kujala’s usage of his system in Kalle Kalima & K-18’s first CD. 5)

Krassimir Sterev: “–Quarter-Tone” Stop Layer (2005)

Also in 2005, Bulgarian accordionist Krassimir Sterev collaborated with Viktor Melnik to retune two right-hand stops a quarter-tone lower. 6)

  • Right manual: out of four stops, two are tuned –¼-tone (8′ non-cassotto and 4′ piccolo); the other two stops (16′ cassotto, 8′ cassotto) remain semitone.
  • Left manual: unchanged, semitone.
  • Keyboard: remains the standard chromatic button arrangement.

This adaptation embeds quarter-tones into the familiar accordion structure. Composers including Peter Jakober and Elisabeth Harnik have written works for this system. A 2017 ORF feature described the result as “micro-intervals at the press of a key.” 7)

This design may be described as an enhanced classical accordion with a “−¼-tone layer.”

Srđan Vukašinović: The Multituning Accordion (2008–2010)

Between 2008 and 2010, Serbian-Swiss accordionist Srđan Vukašinović collaborated with the Zurich University of the Arts (ZHdK) and Bugari Accordions to develop what he called the Multituning Accordion. 8)

  • Right manual: instead of a standard 5-row chromatic button system, the keyboard was built as two independent 3-row units placed side by side. Since three rows suffice to cover the complete 12-EDO system (the extra two rows on standard instruments are mechanically coupled duplicates), this design allowed one unit to be tuned in normal semitones, and the other a quarter-tone apart.
  • Left manual: unchanged, semitone.
  • Conceptual result: this creates two parallel 12-EDO systems offset by a quarter-tone, giving access to all 24 notes of the octave. The principle is therefore closer to a double-manual within one keyboard than to a single unified 24-EDO isomorphic system such as those of Kujala or Amenabar.
  • Context: developed as a research project at ZHdK, with Bugari Accordions constructing the prototype.
  • Documentation: Vukašinović is reported to hold a patent, but very few references are available publicly, and no exact filing date could be verified.

This design stands as another example of a dedicated quarter-tone accordion, though documentation is sparse.

XAMP Microtonal Accordion (2015–2016)

The XAMP duo (Fanny Vicens & Jean-Étienne Sotty) adopted a parallel approach: adding a quarter-tone layer to a standard concert accordion, but in the upward direction. Built between 2015 and 2016, with tuning by Philippe Imbert, their XAMP microtonal accordion has: 

  • Right manual: out of four stops, two are tuned +¼-tone (16′ cassotto and 8′ non-cassotto); the other two (8′ cassotto, 4′ piccolo) remain semitone.
  • Left manual: unchanged, semitone.
  • It supports pure and mixed registrations, enabling spectral and beating timbres in ensemble performance.

Both Sterev’s and XAMP’s instruments share the same principle: preserving the standard layout while adding a microtonal layer—implemented downward by Sterev and upward by XAMP. 9)

This design can also be described as an enhanced classical accordion with a “+¼-tone layer.”

Lore Amenabar Larrañaga: Fully Quarter-Tone Double Manual (2018–2020)

Between 2018 and 2020, accordionist Lore Amenabar Larrañaga designed and had built by Bugari Accordions a fully microtonal instrument.

  • Both manuals: fully tuned to 24-EDO with an isomorphic keyboard layout.
  • Visual ergonomics: quarter-sharp and quarter-flat notes are marked with blue-colored buttons (inspired by the Fokker organ), aiding orientation.
  • Context: developed as part of Amenabar’s doctoral research at the Royal Academy of Music.

Amenabar regards this instrument as the first to be purpose-built from the ground up for complete microtonal functionality. She has since commissioned numerous works, documented on her 2023 release Ispilu. 4) 10) 11)

This instrument represents another form of dedicated quarter-tone accordion.

References

  1. Veli Kujala, “On my music and beyond: Towards the golden era of the classical accordion,” Finnish Music Quarterly, Dec 2024.
    https://www.fmq.fi/articles/on-my-music-and-beyond-towards-the-golden-era-of-the-classical-accordion

  2. “The Arabic Accordion,” MaqamWorld.
    https://www.maqamworld.com/en/instr/accordion.php

  3. Sampo Haapamäki, Velinikka (2008). Work page and program note.
    https://core.musicfinland.fi/works/velinikka

  4. Lore Amenabar Larrañaga, Quarter-Tone Accordion: (Un)Defining a New Musical Instrument with New Music. PhD Thesis, Royal Academy of Music London, 2023.

  5. Wieslaw Ochwat’s Article Individual Creative Conceptions in Polish Solo Accordion Music in Claudio Jacomucci (editor), Modern Accordion Perspectives #4 “Expert Musicianship”, Youcanprint, 2018.
    https://www.claudiojacomucci.com/publications.html

  6. Lore Amenabar Larrañaga, PhD Thesis.

  7. “Kontraforte und Ikea-Blockflöte,” ORF Ö1, feature including Krassimir Sterev’s quarter-tone accordion. 8 Apr 2017.
    https://oe1.orf.at/artikel/212590/Kontraforte-und-Ikea-Blockfloete

  8. ZHdK “Tag der Forschung” (2010). Srđan Vukašinović, Multituning Accordion (in Vierteltönen), in cooperation with Bugari Armando Accordions.
    https://www.zhdk.ch/en/event/9620
    PDF programme: https://www.zhdk.ch/file/live/77/776e439a7b0cd3c28c110177fb89dc3d29816a8d/9620.pdf

  9. Fanny Vicens & Jean-Étienne Sotty, “L’accordéon microtonal XAMP : gestation, fabrication et évolution d’un nouvel instrument,” La Revue du Conservatoire, no. 5 (June 2017).
    https://larevue.conservatoiredeparis.fr/index.php?id=1618

  10. Ispilu digital booklet, Divine Art Recordings (2023). Design and build details of Lore Amenabar’s quarter-tone accordion.
    https://d2ajug1vehh95s.cloudfront.net/77108booklet.pdf

  11. Ispilu – Works for Quarter-Tone Accordion, Divine Art Records, release page (2023).
    https://divineartrecords.com/recording/ispilu-works-for-quarter-tone-accordion/