1. program notes
2. technical details
3. performances

programme notes

The present music notation system is based on twelve-tone equal temperament, corresponding to semitones, meaning that not all frequencies and pitches may be captured. Expanding the present system to a 24-tone or even 48-tone tempered tuning, corresponding to a resolution of a quarter tone and an eighth-tone respectively, will lead to a larger choice of pitches, yet still entails approximation of frequencies into a notation grid (quantification).

Rozalie Hirs composed the honeycomb conjecture for large ensemble and electronic sounds (2015) in a continuum of frequencies. This means that Hirs first calculates frequencies and other musical parameters to generate the electronic sounds, as well as the instrumental score performed live. For the score of the honeycomb conjecture Hirs, then, approximates the resulting the frequencies to the nearest semitone, while indicating the cents deviation above the notated pitch. This deviation is a percentage with respect to the nearest semitone written in the score.

The electronic sounds in Hirs’ compositions are synthesized using the non-approximated frequencies and provide a means of reference of the absolute pitches for the musician during rehearsal and performance. In this way the role of the electronic sounds is two-fold, both as constituent to the music as well as a reference base for the performer: the electronic sounds shape the overall music and inform the instrumentalist how to adjust the intonation of the written pitches.

With special thanks to Casper Schipper for assistance with the sound synthesis in SuperCollider and to Jan Panis for the sound projection in the hall.

technical details

the honeycomb conjecture for large ensemble and electronic sounds (2015) by Rozalie Hirs was commissioned by Philharmonie, Essen, Germany, for Festival NOW! Prismen. It was first performed by ASKO|Schönberg and Reinbert de Leeuw (conductor) on 8 November 2015.

2 flutes
bass clarinet

2 French horns
2 trumpets
bass trombone

2 percussion
keyboard (electronic sounds)

2 violins
2 violas
2 cellos
double bass

a MIDI pedal for triggering the electronic sounds, to be played by one of the musicians, and laptop

13′ ca.

further technical requirements
1.) keyboard, connected to laptop with QLAB software installed
2.) The ‘the honeycomb conjecture’ QLAB sampler, to be obtained through Deuss Music.
3.) Amplifier and mixer in the concert hall
4.) Stereo loudspeakers, to be placed within the ensemble
5.) Optional amplification of the ensemble (i.e. microphones, cables)

Rozalie Hirs’s music scores are published by Deuss Music. Score and parts of the honeycomb conjecture (2015) can be purchased through this link (click here).


8 November 2015, 10:00 CET, Festival NOW! Prismen, Philharmonie Essen, Essen, Germany – ASKO|Schönberg, Reinbert de Leeuw (conductor)

The above picture by Rozalie Hirs shows the rehearsal her new work the honeycomb conjecture (2015) with ASKO|Schönberg and Reinbert de Leeuw at Philharmonie Essen on 8 November 2015.