Karlheinz Essl

Checkin' my Shrutis...

Meditative drone scape based on 25 chords of a Shrutibox
Album release: 4 Aug 2019

Download | Liner Notes | Biography

Recorded, edited and mastered by Karlheinz Essl at Studio kHz
Released on 4 Aug 2019 by Nachstück Records

Total duration: 2:49:09 (two tracks)

Liner Notes

This generative drone scape is based on a sequence of 25 chords which have been recorded by Karlheinz Essl on a Shrutibox - an instrument which used in traditional Indian music for creating long drones. The sound is produced by slowly moving a bellow which creates an airflow that is directed towards a series of pipes fitted with reeds. These pipes can be opened or closed with adjustable buttons. By this, a large variety of chords can be created out of 13 chromatic pitches within a single octave.


The sequence of 25 chords played on a chromatic Shrutibox
© 2019 by Karlheinz Essl

The piece starts with the note F, and slowly moves towards the dyad F-C, the perfect fifth which is often used in classical Indian music. The next chords is D-F-C, followed by the four-part sound D-F-G-C. In the fifth chord, the diatonic system is broken by replacing the D by C#. From there on, all chromatic notes are used until chord #12.

In the transitions from one chord to another, only one pitch changes which results in a very slow harmonic transformation. However, the progression does not simply move in one direction. Instead, a helix-like process is introduced that always goes back to the origin (sound #1, the F) before it reaches a new chord:

1 2
1 2 3 2
1 2 3 4 3 2
1 2 3 4 5 4 3 2

The entire process lasts 12 hours before the whole hypercycle will be starting again. This release, however, only contains the first part with a duration of approx. 3 hours.

The piece was created by computer program written in Max, using compositional algorithms from Karlheinz Essl's Real Time Composition Library (RTC-lib, a open-source software library for Max). Time stretching, tiny pitch deviations and the careful use of flanger and reverb create a everchanging drone scape with a surprisingly rich inner life, ideal for deep listening, meditation, and relaxation. It's cosmic music without being esoteric!


Recording of the chromatic Shrutibox
Studio kHz, June 2019


Karlheinz Essl, born 1960 in Vienna. Composer, improviser and performer. He studied composition with Friedrich Cerha and musicology in Vienna. Besides composing instrumental and electronic music, he performs on his own electronic instrument m@ze°2, develops software environments for computer-aided composition and creates generative sound and video environments. Composer-in-residence at the Darmstadt summer courses, IRCAM (Paris) and the Salzburg Festival. Between 1995-2006 teaching „Algorithmic Composition” at the Bruckner University in Linz. Since 2007 professor of composition for electro-acoustic and experimental music at the University of Music in Vienna.

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Updated: 5 May 2020