"Just intonation" is an ideal tuning of pitches, improving natural sounding of the chords. It is often used intuitively in polyphonic songs, giving a specific color very pleasing to the ear.
Classified as utopia centuries ago, equal temperament has been preferred by western music, dividing the octave into 12 equal semitones. This compromise allows the construction of contemporary western music as we know it today, and the playability of the keyboard instruments (piano, ..) in all tones and modulations.
Using the Expresseur, the just intonation in instrumental accompaniment is very easy. The software tunes the pitches in real time. Chords are all naturally tuned, whatever the complexity of modulations.
The musical indications to add in the score are very simple: the root of the chord, and, if necessary, the unchanged pitch between chords (pedal ..). The software performs all necessary calculations and realization during the live performance !
Thanks to the Expresseur, it becomes easy to accompany singers, guiding and supporting them precisely in just intonation (which is impossible with a conventional keyboard instrument using a static tuning). The ability to have multiple audio output can even support each voice separately (Bass, Soprano, ...)
The use of just intonation can be considered obsolete. Several centuries of equal temperament suppressed more or less the ability to hear the added value of just intonation in polyphony. Contemporary sound modulations (vibrato, pitch-bend...) reduce or override the subtlety of just intonation.
But, perhaps, the just intonation, finally available for instrumental accompaniment, can trigger new ideas , not only by revisiting classical scores (Roland de Lasus, ...), but also creating new styles (contemporary polyphony sung with "instrumental" accompaniment ).
Using just intonation with the Expresseur :
- By default, Zarlino natural scale is set in the Hardware tab. It can be changed if necessary.
- Sound expander : an SF2 must be connected in the Hardware tab, or MIDI expander(s) compliant with the Sysex « scale/octave tuning 1-byte form » ( e.g. Roland SD-50 ).
- Tone selection : to appreciate just intonation without difficulty, it's easier to use a simple sound, like a puff organ ( e.g. SF2 available on Expresseur web-site, or the puff-organ in the Roland SD-50 ).
- Improvement of the original score : create a track named "scale root". This track will not be played by the Expresseur : it will contain indications to tune the scale dynamically. Its content is similar to a bass track. A single note selects the root of the scale. Optionally, a second note at the same time specifies the common pitch which is part of previous chord and new one, and which must not be detuned ( pedal, … ). A note with a cross-shaped head resets equal temperament. An example of score is available in the web-site : Bonjour Mon cœur / Roland De Lasus
- Verification : menu "tool/ tuning shift" displays the change of the pitches along the score. It can help to detect an important shift of the tuning, generally triggered by too many inappropriate common pitches.
- Performance : just play the score as usual. And enjoy the difference …
Other use :
- "just intonation" training for singers in a choir, using imitation : each voice can have its own separate soundtrack, linking each track to one MIDI channel, linked to one single audio channel (e.g. two stereo MIDI expanders for 4 audio channels fully separated).
- Menu "tool/Test A4" resets equal temperament before to play the A4.
- Root of the scale and common pitch can be set in object "tuning". This object, available everywhere in the software, can be used for presets, or in the Translator for improvisation.
- Root of the scale can be set in real time using a specific MIDI channel ( Hardware tab )
- Ctrl-change 119 resets equal temperament