Klangmoraste: More Information

On the composition:

Klangmoraste may be realized in 17-tone equal temperament. Due to the size of the tenth scale degree equaling the interval of a fifth (705.9 ct), the pitches of the circle of fifths appear stretched in this tuning in respect to 12-tone temperament.
Hence, the string player intonate in a ‘leading-tone’ fashion; the piano part has to be realized on two pianos (with identical white and enharmonic black keys), and the wind players tune their pitches individually to the pitches presented by the MAX patch. The steel bar instrument has to be replaced by a synthesizer, unless the tuning cn be applied to an acoustic instrument. If the pianos need to be substituted by a keyboard, sequencing of the piano passage from measure 67 (B) to measure 95 (two measures before C) is recommended.

Tuning pitch is middle a (= 440 Hz)

The following setup was realized for the first performance of the 17 tone/electronic version by the Ensemble Modern


  1. Apple Macintosh Computer with at least 2 MByte RAM
  2. YAMAHA SY77 synthesizer
  3. YAMAHA KX88 master keyboard (it may be replaced by any master keyboard with 88 keys and MIDI-merge capacities)
  4. Anatek Pocket Pedal
  5. 4 foot switches
  6. 4 MIDI cable (of different length)
  7. Multi channel stereo mixing console and amplification

The following graphic displays the setup on stage:




The MIDI processes were controlled by the Klangmoraste patch written in the modular programming environment MAX (by Opcode Systems; the patch is available from the composer on request). All the necessary setups of the synthesizer are accomplished by sending MIDI system exclusive messages. (Activate the Klangmoraste-subpatch Lies_mich/Read_me by double-clicking on the corresponding icon and starting the data transfer.)


The player of the keyboard with the vibraphone sound (SY77) controls the (enharmonic) assignment of pitches to the black keys by using a foot pedal (if the pedal is released all black keys correspond to sharp notes (e.g. c#), and if the pedal is pushed down they all correspond to flat notes (e.g. db). In addition to the sustain pedal (controller no. 64) this pedal has to be connected to the foot switch input of the SY77 (assigned controller no. = 63). Those moments when the pedal has to be pushed are indicated in the score. The vibraphone part on the SY77 has to be played an octave lower as written.
The plucked tones contained in the piano part should possibly be realized on an acoustic piano. If the piano solo (from rehearsal mark B) is ought to be performed by computer then the conductor starts the sequence by pushing his/her foot pedal. It should be taken care that micro switch no. 7 of the Anatek Pocket Pedal (start/stop) is activated exclusively. The Anatek box also needs to be initiated by some MIDI input from the keyboard.


A note on the algorithmic composition technique used in Klangmoraste:

1. Melody and harmony

Klangmoraste for chamber orchestra and electronics was written for a specific tuning (17-tone equal temperament), but can also be performed in standard 12-tone equal temperament. An 81-tone pitch set based on the closed circle of 17 fifths (that exists in this particular tuning) served as the basic melodic and harmonic material.

This set was generated by designating middle D as the tonal center and determining the occurrences of the pitches by harmonic distances in the following way:

D: 9 occurrences, A and G: 8 occurrences, E and C: 7 occurrences, etc., Gb and A#: 1 occurrence.

The set of pitches was split in two symmetrical halves and organized into melodic cells with growing melodic complexity (algorithmically produced and rearranged according to intuitive preferences):

0 1 2 – 1 3 2 – 0 1 3 4 2 – 1 3 4 5 1 2 – 0 1 3 6 5 4 2 – 1 3 6 4 5 7 2 0 – 1 3 6 7 8 5 4 2 0.

(The numbers determine the distance from center-D in terms of fifths.)

In order to distribute the 17 fifths over the available range of the orchestra, the fifth progression was modified in such way that after two consecutive ascending fifths the row folds back by leaping down a fourth, e.g. D4-A4-E5-B4-F#5 etc.

By diatonically filling the holes produced by this progression, a non-octavic mode (whole step – whole step – whole step – whole step – half step) emerged with the major sixth as the frame interval.

I derived a pseudo-tonal language by combining the fifth progression with the descending scale notes:

Dyads: D/D – A/C# – E/B – B/A – etc.

This effect was amplified by using the inversions of both the scale tones and fifth progression yielding four-note chords:



Within these chords the pitches of the fifths progression were occasionally doubled (a few octaves higher or lower).

2. Rhythm and form:

The duration of a chord, and therefore the harmonic rhythm, was set by the number of scale steps between the scale tone and the pitch belonging to the fifths progression (both ascending):

D-D: 8, A-Eb: 4, F-E: 7, G-B: 3, A-F#: 5, etc.

A computer-aided, stochastic process operating on the 41-tone row generated the global structure of the piece. For this, a set of rules controlled the growth of the row in time (analogous to “protein translation” in molecular biology).

These rules are:

Leaping: At given points there is a probability for a leap to another point in the row.

Repetition: There is a given probability for repeating a certain chord.

Retrograde: There is a given probability for moving into the opposite direction.

I used a program written in GFA-Basic on an ATARI 1040 in order to extend the row so that it would yield approximately 6 minutes of music. Three runs were necessary to produce a musically convincing result.

The resulting structure was subdivided into five musically distinct sections:

1. Beginning: Homophony.

2. Rehearsal marking A: Homophony and transition to B.

3. Rehearsal marking B: Superimposition of two processes.

4. Rehearsal marking C: Climax (undetermined pitches).

5. Rehearsal marking D: Homophony and breakdown.


3. Orchestration:

The choice of instruments was determined by the drama of the five sections. Hereby, the tuning imposed certain limitations that had to be met by the instrumentation, e.g. 8 wood winds. (Each wind instrument plays three pitches, tuned to an individual tuning pitch to produce 17-tone equal temperament).

In the 17-tone version, both the celeste and the piano have to be replaced by keyboards and synthesizers. In contrast, the string instruments are able to adjust simply be intonating raised pitches (e.g. c#) sharper and lowered pitches (e.g. db) flatter, which is the “natural tendency” of string players anyway.