The multiphonics morphing fragments follow similar steps of extracting orchestral harmony from tam-tam spectra. Flute and string notes in the previous catogory gave rich timbres, limited to sampled long notes. Multiphonic sounds are richer sound phenomena, it is harder to find a "base note" through a sampler logic.
The Catart tools1 developed at Ircam enable sound categorizations by parameters like high frequency content, mid frequency content, high frequency energy, spectral centroid, spectral flatness, periodicity, loudness, pitch, duration and other sorting criteria. It could offer more flexible classificatons of complex sound phenomena.
For this project I have tried to stretch classification by pitch as far as possible, as part of this project is exploraton of tuning systems. Even though there were cases neither a pitch analysis nor my ears could be sure about a single reference pitch. The notations are in these cases useful to generate results, not as a sufficient representations of a sound.
"A common approach to sound-composition is to define "instruments" - either by manipulating factory patches on a commercial synthesizer, or by recording sounds on a sampler - and them trigger and transpose these sounds from a MIDI keyboard (or some other kind of MIDI controller). Many composers are either forced into this approach, or do not see beyond it, because cheaply available technology is based on the note/instrument conception of music. At its simplest such an approach is no more than traditional note-oriented composition for electronic instruments, particularly where the MIDI interface confines the user to the tempered scale." 2
A possible conflict exists between composing with notes or timbres. Tunings systems can create transitional zones between chords and timbres, perceptions of fine nuances of intonation require multiple sounds with centered pitch. It will be possible to apply timbral transitions and spatializations to individual parts of these virtual orchestras, and the ”instruments” of this orchestra can be any kind of sounds. A work can maneuver between work on melody and harmony, and transition into multidimensional timbral phenomena.
There were two groups of multiphonic sounds.
Woodwind multiphonics (a few selected multiphonics on flute, oboe, clarinet and bassoon).
Contrabass multiphonics. Håkon Thelin3 has specialized in new techniques for the contrabass. Harmonic finger pressure and detailed control over bowing techniques at harmonic nodes along the strings enable stable multiphonic sounds, in some cases almost comparable to those of the woodwind instruments. We recorded:
Stable multiphonics.
Transitions from multiphonics to crush notes.
Morphing sounds between these two types of sounds made the source sounds less recognizable. Reasons may be:
The sounds do not have clear centered pitches, but harmonies and timbres. Even though vaguely similar reference pitches have been attempted, the sounds are not similar enough for smooth transitions. The results could not be confused with acoustic instruments.
The contrabass sounds are generally shorter than the woodwind sounds. The FFT4 stretches are audible, and the contrabass is less recognizable than the woodwinds.
The goal may not necessarily be realism, but finding different degrees of familiarity through transformations.
Example 4: Multiphonics-morphing 13.
Example 5: Multiphonics-morphing 47.
Example 6 : Multiphonics-morphing 58.
Example 7: Multiphonics-morphing 70.
Example 8: Multiphonics-morphing 77.
A virtual morphing orchestra can for future projects involve many more orchestral timbres, within traditional and extended techniques. I have for these sound installation fragments chosen to narrow the range of sounds down to these few selected string and woodwind sonorities.
2 Trevor Wishart, 1994, Audible design, p. 2.
4 Fast Fourier Transform.