Karlheinz Essl

Portrait KHE

Checkin' my Shrutis...

generative drone scape based on 25 chords played on a chromatic Shrutibox

Karlheinz Essl schaltet sich mit respektvoll-sicherem Griff in den unerschöpflichen Kanon der musikalischen Töne ein, betrachtet in vielfacher Vergrößerung, Verkleinerung, Veränderung den ausgesiebten Schatz an Gefundenem, gibt ihm behutsam-kontrollierte Drehungen, die wiederum neue Facetten ans Tageslicht bringen, gießt die so gewonnene und in Bewegung geratene Ton-Masse in eine kunstvoll geschmiedete Klangschale, deren Eigenschwingung wiederum in unterschiedlicher Dichte bis in die letzten Winkel des bespielten Raumes fließt. (Jörg Duit)

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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.


The piece was created by computer program written in Max, using compositional algorithms from my 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!


The Very Drone Scape Generator, written in Max
© 2019 by Karlheinz Essl


Checkin' my Shrutis... - first hour out of twelve
Recorded by Karlheinz Essl on 9 Jul 2019 at Studio kHz

Binaural soundwalk through Checkin' my Shrutis
Recorded by Karlheinz Essl on 7 Nov 2019

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Updated: 8 Nov 2019