Microtonal music is often used to portray another culture, or to experiment with pushing the boundaries of traditional "western music". But it has other potential uses. One very effective use of microtonal music is for when you want a scene or character in a film or game to feel a little off, like maybe something isn't quite right. An example is from my score to the short film Ten Years Later. In this film, the main character has just been released from spending ten years in prison and is now seeking revenge against her sister, who testified against her. The lead character has lost her humanity, and the directors wanted the music to reflect that sinister darkness that is growing within her.
19 Tone equal temperment
The Ten Years Later score was my first foray into microtonal music. I wanted a scale that had more notes than the standard twelve. I also wanted to avoid standard-sounding intervals, so I ruled out the 24 tone scale. I decided on using 19 tone equal temperament (aka 19-TET, 19-EDO), which divides the octave into 19 equal intervals. The decision was fairly arbitrary, but it satisfied my requirement of forcing me to find different intervals. It also had the added benefit that it could be notated using traditional music notation, with only a slight-modification: Previous enharmonic spellings of sharps and flats become different notes. In other words: B-flat and A-sharp become different notes. Thus, a chromatic 19-TET scale is spelled:
In this system, the notes C-sharp and D-flat are two distinct pitches. The only enharmonic respellings are E-sharp/F-flat (pitch 8) and B-sharp/C-flat (pitch 19). The standard whole tone that we are used to is divided approximately into thirds (roughly 63 cents), rather than halves (100 cents).
Minor 3rds (6:5) and major thirds (5:4) in 19-TET are closer to the harmonic series than standard 12 tone equal temperament minor 3rds.
Perfect 5ths are slightly further out of tune (flat) from the harmonic series than 12 tone equal temperment.
Here is a comparison of a C major chord in 12 tone equal temperment vs 19 tone equal temperment.
Realizing 19 TET
Logic Pro's microtuning capabilities assume 12 notes per octave, so doing 19 TET with Logic Pro's native sample sets isn't supported. But fortunately, Native Instruments supports 19 TET and many other advanced tunings within most of their virtual instruments. For example, Kontakt comes with a script that will do an arbitrary number of notes in an octave. This animated gif shows how to set up 19 TET within Kontakt.
I've also successfully done 19 TET within Absynth and Massive.
examples of Game and Film music using 19 TET
In the short film Ten Years Later, I used 19 TET tuning to portray the growing darkness within the lead character.
In the competitive word game, Wordlings, I use 19 TET tuning to create a quirky, off-kilter vibe. The alternate tuning also evokes the out-of-tuneness of vintage chiptunes music from some early video games and home computer audio chips.
19 TET-based Sound design
It's also possible to use alternate tuning systems in SFX-creation. In my next blog post, I will show how I used 19 tone equal temperament in the game Wordlings to create synth-based SFX that sounded less "musical" while also matching the music.