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Colourative effects

In the following, I will present effects that determine the colouration of multiphonic sounds. There are multiple combined techniques that are used in a great number of works, and my aim has been to provide a thorough presentation of existing techniques and their practical utilisation in a selection of composed works. The multiphonic technique is still in its early stages of development, and there are many more sounds to be discovered. This general presentation can be seen as a first excursion in to the field of multiphonic sound effects and will hopefully serve as an impulse or inspiration for further explorations into this technique, by both performers and composers.

Transformation

Semitonic multiphonics can be transformed into harmonics, ordinary tones or other sounds. In Foxfire Zwei, I use the gradual change between multiphonics, harmonics, fundamental and air sounds, to create living sounds, constantly changing the colour of the multiphonics. In example 1, the sounds change gradually between multiphonic, harmonic and air sounds (created by damping the string with the left hand and playing with a light bow). The changes between multiphonic and harmonic sounds are caused by small changes in bow position, pressure and speed.

Ex. 1. Transformation between multiphonic, harmonic and air sounds. Helmut Oehring: Foxfire Zwei (arr. Håkon Thelin)

Transformations from harmonic to multiphonics are possible through changing the spot at which the bow touches the string and by applying additional pressure to the string (Liebman, Movement of Repose, New sounds for cello and double bass, page 31). The bow must be moved to a central harmonic node, which facilitates the creation of the multiphonic sound. A smooth transition can be controlled by manipulation of bow pressure and bow speed. Usually this means applying more pressure to the string and bowing with a slightly reduced speed. Illustrations of this effect are shown in example 2 and 3. In example 2, the bow should move to the central harmonic node position 13 when modulating into the multiphonic sound.

Ex. 2. Transformation from harmonic to multiphonics. Håkon Thelin: Light

Ex. 3. Transformation from harmonic to multiphonics. Michael Liebman: illustration from Movement of Repose, New sounds for cello and double bass

In Thrust, Kimmo Hakola makes use of sound transformations by alternating multiphonics and ordinary tones. The effect is a rather quick in-and-out transformation of the sound. The bow pressure must be precisely synchronised with the left hand movement in order to get the full effect of the changing sounds.

Ex. 4. Transformation between multiphonics and ordinary tones. Kimmo Hakola: Thrust, page 7, Rubato (Adagio)

The transformative process seen in example 5 shows an artificial multiphonics on the E-string, to be played together with the open A-string. This artificial multiphonics dissolves into an open string, which again is gradually converted into a multiphonic sound as the finger slowly dampens the string over the E-flat harmonic. The bow position indicated above the stem (B E22↓ and B13) is notated in accordance to figure 3 and example 5b in the chapter on Bow placement.

Ex. 5. Transformation from artificial multiphonics, via open string, to semitonic multiphonics. Håkon Thelin: Glasperlenspiel

Tremolo

Tremolo is possible on most multiphonics. The effect is usually a noisy, complex, and often, unstable sound. The types of multiphonics that are easy to play, give the most stable noise-like sounds when playing tremolo. Example 6 includes this effect with tremolo multiphonics on the second and third strings, the sounds being initiated by slightly accentuated grace notes. All the multiphonic sounds in this example are rather easy to play.

Ex. 6. Tremolo. Håkon Thelin: Shared moments

Example 7 illustrates ordinary multiphonics going into tremolo multiphonics and vice versa.

Ex. 7. Going in and out of tremolo. Helmut Oehring: Foxfire Zwei (arr. Håkon Thelin)

When applying tremolo on multiphonics that are more difficult to play, careful attention must be given to finger pressure, bow position and bow pressure, for the sound generally fluctuates more randomly between the overtones.

Multiple variations of the tremolo effect are possible, e.g., changing bow speed (slow or fast tremolo), changing bow pressure (greater pressure creates a harder, more noisy sound while less pressure gives a brighter, airy sound), and changing bow position (this can enhance certain overtones of the cord as well as the overall timbre of the cord).

Vertical vibrato, hammer-on multiphonics and legato tremolo

Michael Liebman employs what he calls a vertical vibrato to multiphonics: ”By rapidly varying the amplitude of finger pressure on a string from slight to deep (almost, but not actually touching the fingerboard), we achieve the vertical vibrato[...]” (Movement of Repose, New sounds for cello and double bass, 2010, page 35). Hitting the string against the fingerboard creates a variant of this technique. Liebman writes ”[…] in such cases, in addition to the multiphonic chord, a "flickering" tone is produced corresponding to the point where the finger touches the fingerboard” (Ibid., page 35). The presence of the stopped note in the sound can also be controlled by how hard the finger hits the fingerboard. I will refer to this technique as hammer-on multiphonics.

Liebman further describes an open string tremolo where the player rapidly alternates between touching the string and raising the finger. An effect I would describe as a legato tremolo between the multiphonics and the open string. It is possible to control the presence of the fundamental tone through the force of the finger that pulls the string; contrary to the faint fundamental sound that is perceived when the finger is only lifted (and not pulled) from the string.

In example 8, the first action is a vertical vibrato (where the finger does not touch the fingerboard), followed by a legato tremolo between the multiphonics and the open string. I would interpret this particular legato tremolo as to be performed only with a slightly lifted finger, so that the change of timbre is only scarcely audible, and led naturally on from the vertical vibrato. The third action in example 8 is a rhythmical vibrato, the effect being created when the finger softly hits the harmonic a half note above the multiphonics. Make sure that the multiphonic sound is kept constant throughout the action.

Ex. 8. Vertical vibrato, legato tremolo and rhythmical vibrato. Michael Liebman: Sonata for double bass, 2.movement Legato sonore

The different types of vibrato, legato tremolo and hammer-on multiphonics are relatively idiomatic techniques. They open up a wide area of rhythmical possibilities as well as means of colouring multiphonic sounds. In Shared moments (2009), I use hammer-on multiphonics, which, during the course of interpretation was played as a sound that rapidly alternates between and blends the multiphonics, stopped note and open string. The notation in example 9a and 9b, however, is still the same as with hammer-on multiphonics. The techniques can be seen in the context of the longer musical line in example 9c.

Ex. 9a. Hammer-on multiphonics. Håkon Thelin: Shared moments

Ex. 9b. Hammer-on multiphonics. Håkon Thelin: Shared moments

Ex. 9c. Hammer-on multiphonics. Håkon Thelin: Shared moments

Example 10 shows a legato tremolo on the A-string with a flageolet trill on the F♯ on the D-string, while a variation is shown in example 11 where a legato tremolo on the A-string is combined with an artificial harmonic on the D-string. The two multiphonics used in these examples are easy to play and most bow positions work well. The occurrence of artificial harmonics, however, calls for a placement of the bow somewhere towards the bridge, although not necessarily sul ponticello.

Ex. 10. Legato tremolo combined with artificial harmonic trill on the adjacent string. Håkon Thelin: Light

Ex. 11. Legato tremolo combined with artificial harmonic on the adjacent string. Håkon Thelin: Light

In a passage from Glasperlenspiel, shown in example 12, I use legato tremolo and hammer-on multiphonics in a play with timbre and harmonies. The first action is a legato tremolo on the D-string, where the multiphonic sound blends with the opens string. A crescendo brings the sound into a hammer-on multiphonics on the E-string. The hammered C perceives as a fundamental, with intermingling partials of the E-string multiphonics. The open strings, plucked as appoggiaturas with the left hand, resonate with the legato tremolo multiphonics, which is now stripped from the C fundamental. The sound again rises through a crescendo into hammer-on multiphonics on the A-string, where the E-flat fundamental intermingles with the A-string partials, sounding together with the appoggiaturas of the E and G-strings.

Ex. 12. Legato tremolo and hammer-on multiphonics. Håkon Thelin: Glasperlenspiel

A technique that is not shown here, but waiting to be explored later on, is the legato tremolo between multiphonics and either an open string, harmonic or stopped note on an adjacent string.

Richochet

Example 13 illustrates the opening of Shared moments. The musical gesture of this opening is repeated several times during the entire piece and can be seen as a play with timbre and resonance between the four strings. Each note is coupled with a unique attack: the short notes are played with left hand pizzicato and with the tip of the bow, while the long notes are played with a bouncing bow. A ricochet on a multiphonics then establishes the first extended tone with an accentuated and quick bouncing bow in order to release the multiphonic sound. This sound leads to the second attack where a (quick) ricochet transforms into a vertical bouncing bow, called rimbalzo verticale by Stefano Scodanibbio, which is characterised by a soft, flickering sound.

Ex. 13. Richochet. Håkon Thelin: Shared moments

Playing simultaneously on two adjacent strings

By adding the additional tone of an adjacent string new colours may be added to a "tonal" sounding multiphonic chord. This change may vary from a slight coloration, to dissonance, and even to a complete transformation of the colouring.

1. Multiphonics with an open string

In example 14 we see an artificial multiphonics played together with an open A-string. The bow position for the artificial multiphonics is assigned to the 10th harmonic partial on the E-string. The added open A-string darkens the sound and gives a slight perceptible harmonic feel in the minor third interval between the fundamental tones (G♭-A).

Ex. 14. Artificial multiphonics played together with an open A-string. Håkon Thelin: Glasperlenspiel

The static sound that we meet in the previous example comes to life through trills and glissando movements of the multiphonics in example 15. A rumbling, full sound is heard when the glissando slowly moves towards the sound of the open string. The fundamental and the overtones in the multiphonics create a complex, constantly changing, set of interference tones with the open string drone. As in the previous example, the bow can be placed on the 10th harmonic partial on the E-string, but must be moved proportionally with the left-hand glissando up the string.

Ex. 15. Artificial multiphonics trill played together with an open A-string. Håkon Thelin: Glasperlenspiel

2. Multiphonics with a natural harmonic

Ex. 16. Multiphonics with a natural harmonic. Maja S. K. Ratkje: On Wombs and Vowels

In her piece On Wombs and Vowels, Maja S. K. Ratkje uses a combination of multiphonics and natural harmonics. This does not change the bright sounding colour of the overtones but adds a dimension to the harmonic spectrum. The notation is practical and easy to read: In the first bar, the harmonics (top notes) are played on the first string while the multiphonics (bottom notes) are played on the second string. In the second bar, the multiphonics are the same as in the previous bar but with the harmonics played on the third string. In bar three, we have a new set of multiphonics on the third string that is played together with harmonics on the fourth string. The gradual descent from high to low strings creates a change of colour from bright to dark. On the low strings the cords have a full sound with much resonance, while the brighter sounding chords on the higher strings sound more restrained and are also more difficult to play. Bow placement is left to the decision of the performer. There are multiple options, in order to bring out the sound of the harmonic, however, a placement relatively close to the bridge is preferable.

Examples 17 and 18 are taken from the double bass solo that opens Giants of jazz (1999-2001), a piece by the Norwegian composer Øyvind Torvund. The top stave indicates the rhythm of the bowing as well as the sounding note of the harmonics, which is notated on the lower stave and played together with normal tones or other harmonics. Towards the end of the system, the phrases are closed with combined sounds of chords consisting of multiphonics and natural harmonics. The multiphonic chords are not notated, but are marked as a cluster sound.

Ex. 17. Multiphonics with a natural harmonic. Øyvind Torvund: Giants of Jazz

Ex. 18. Multiphonics with a natural harmonic. Øyvind Torvund: Giants of Jazz

3. Multiphonics with a natural harmonic trill

As illustrated in example 19, this combination lets us play multiphonics together with a trill of natural harmonics on an adjacent string.

Ex. 19. Multiphonics with a natural harmonic trill. Håkon Thelin: oibbnadocS

Here we move from a flageolet trill on the second string, coloured by the gradual movement of the bow, into a multiphonics together with a natural harmonics trill. The effects of both sounds are similar, the multiphonics functions as a stable summary of the floating overtones of the previous action while the additional trill continues the established action and enrichens the harmonic spectrum.

Michael Liebman includes the same technique in his Sonata (example 20), but uses a different notation. He classifies this technique as ”chord and harmonic with tremolo”, and describes: “[…]such a tremolo effect produces a variety of additional overtones. In ponticello, even a slightest shift of the bow gives a new overtone, thus varying slightly the effect on each repetition.” (Movement of Repose, New sounds for cello and double bass, 2010, page 38). The variety of additional overtones creates a strongly fluctuating sound, which can be differentiated even more by moving the bow towards the bridge.

Ex. 20. Multiphonics with a natural harmonic trill. Michael Liebman: Sonata for double bass, 2.movement Legato sonore

In example 21, I have used a sustained multiphonic sound together with a trill between a flageolet and the open string on the adjacent string. The combination shown here is easy to play because I use one of the most stable semitonic multiphonics on the fourth string the augmented 4th in the first octave. In this case, it is, therefore, not necessary to notate a specific bow position.

Ex. 21. Multiphonics together with a trill between a flageolet and the open string on the adjacent string. Håkon Thelin: Shared moments

Example 22 shows the same technique as used in the previous example, yet shifted to the higher strings (third and second strings).

Ex. 22. Multiphonics together with a trill between a flageolet and the open string on the adjacent string. Håkon Thelin: Light

4. Two multiphonics together

It is generally very difficult to play sustained chords of two multiphonics together. Even though the same bow placement applies for both multiphonics, the bow resistance (speed and, most often, pressure) differs from string to string, making it difficult to avoid slips that break the sound. In Glasperlenspiel I made an attempt of combining two multiphonics, with a defined bow position moving from B13↓ on the first single multiphonics, to the slightly lower position of B11↓ for the combined multiphonics. The bow position one octave higher (B13 to B11) also works well with these multiphonics, although the bow speed and pressure react differently when changing octaves with the bow.

Ex. 23. Two multiphonics together. Håkon Thelin: Glasperlenspiel

5. Noise-like multiphonic sounds

Glissando between semitonic and quartertonic multiphonics, combined with the open E-string in a noisy passage are found in Kimmo Hakola’s Thrust (1989). The objective here is not to bring out clearly defined multiphonics, but to create as much noise and sound as possible!

Ex. 24: Noise-like multiphonic sounds. Kimmo Hakola: Thrust, page 2, Allegro