Mark, a friend of mine, started work on a short film in December 2017. Focusing on the use and manipulation of light on the subjects, the film is experimental in nature, very minimal, and incredibly hypnotic.
He asked me to compose and produce an original soundtrack early on in the process of the film, so we got to discuss the intricacies of the soundtrack and it's relationship with the visuals in depth. The soundtrack itself took three days to create, from the first recording to sending off the final masters to Mark.
The soundtrack is 100% ondes Martenot, 11 tracks to be exact. All of the reverb you hear (apart from one use of Ableton's own reverb) comes from LittlePlate by SoundToys, and most tracks have been treated to a little EQ, some occasional compression, and some tactful saturation. There isn't much adventurous processing, save for some pitch-shifted delay on one of the tracks.
Something I wanted to use in this soundtrack was beat-frequencies. Beat-frequencies happen when two tones are so close in pitch that a beating, tremolo-like effect equal in speed to the difference between the tones can be heard. For example, two tones at 137Hz and 139Hz have a difference of 2Hz and, when played together, will produce a 'beating' tremolo effect at a rate of 2Hz.
Interestingly, the way that beat-frequencies work is practically the same as 'heterodyning', which is the process that Maurice Martenot used for tone-generation in the first 6 iterations of the ondes Martenot. Put simply, the vacuum tube oscillators in the ondes Martenot would oscillate at supersonic frequencies, one fixed and one variable. The difference between these two supersonic frequencies was an audible sub-harmonic, which would then be amplified. The Mk. 7 ondes Martenot, first built in 1974, saw this system replaced with a transistor-based system, due to the fragility of the glass vacuum tubes.
Anyway, back to the soundtrack. There are two separate recordings of me playing a drone around C#3 (138Hz), swaying sharp and flat, so the difference between the two pitches is in constant flux. Playing these parts au ruban enabled me to easily access the microtones required to achieve the desired beating effects. These parts were then grouped together and automated in post, to have the volume follow the movement of the light source. In retrospect, I would've liked to have done this manually using the touche d'intensite. Maybe next time. The tone I used for both of those particular parts was 'O', which stands for 'ondes' - a simple sine wave. Other tones used in various combinations were 'N', '8', and 'C'.
The other parts of the soundtrack are simple intervals and repeating phrases that overlap each other at different speeds to provide a dense, shifting bed of texture and harmony.
Two versions of the soundtrack were produced, one was, of course, a simple pass of the soundtrack as it was composed, but the other was designed to accompany a seamless looping exhibition of the video. The second half of the looping version is, essentially, a compositional palindrome of the first half. That was then bounced out and turned into a seamless loop by adding the tail-end of the file to the beginning. The video you can watch here is a version of the looping edit.