Martina Bertoni — Electroacoustic Works for Halldorophone
Electroacoustic Works for Halldorophone is an album by Berlin-based cellist and composer Martina Bertoni, released on February 21, 2025 on Karlrecords. A Dolby Atmos edition was released on February 6, 2026. The album consists of four pieces composed and recorded at Elektronmusikstudion (EMS) in Stockholm in November 2023, using a halldorophone built by Halldór Úlfarsson.
The Album
The four pieces were composed during a residency at EMS Stockholm, where Bertoni used the halldorophone as an algorithmic system to examine tunings and the mathematical relationships between harmonic frequencies. Working with tetraphonic scales applied across both the main strings and the sympathetic string group, she aimed to engage with concepts of time, tuning, and control — specifically exploring interactions that move beyond the composer's direct input.
The album was mixed and mastered by Ciarán O'Shea and lacquer cut by Kassian Troyer at D&M, Berlin.
Tracklist
- Nr.1 Omen in G
- Nr.2 Nominal D
- Nr.3 Fades in C
- Nr.4 Organon in D
The Instrument
The halldorophone is an electroacoustic string instrument built around the deliberate use of audio feedback. It was designed and built by Halldór Úlfarsson, who first developed it as his MFA graduation piece at what is now Aalto University in Helsinki in 2008.
The instrument has eight strings: four main strings played with a bow and four sympathetic strings that resonate through the feedback system. Each string has a dedicated pickup. The signals are fed back through a speaker mounted inside the instrument body, creating a closed loop of mechanical vibration. The player shapes the resulting sound through bow technique and gain control, producing sustained, harmonically dense drones.
The instrument Bertoni used at EMS is the Double Speaker Instrument on loan to Elektronmusikstudion, built in 2023 by Úlfarsson with electronics by Orfeas Moraitis.
Credits
- All music recorded, composed and produced by Martina Bertoni
- Halldorophone recorded at EMS Stockholm, November 2023
- Mixed and mastered by Ciarán O'Shea
- Lacquer cut by Kassian Troyer at D&M, Berlin
- Cover artwork by Gregory Cowling / Praxis
- Released February 21, 2025 on Karlrecords
Further Reading
- Electroacoustic Works for Halldorophone — Bandcamp
- Karlrecords
- Halldorophone — Wikipedia
- Bela Blog Interview with Halldór Úlfarsson (2025)