Small but important differences: Christopher Otto’s ‘rag′sma’

Wednesday 3 November 2021

Does this sound funny to you? I think I’ve heard enough music tuned in just intonation lately to stop it sounding immediately ‘weird’, so that the strangeness to be found in Christopher Otto’s multiple string quartet rag′sma is in the complex beauty that arises from a few pure, simple harmonies. The conventional tuning on your keyboard or sequencer is fudged, to tidy away loose ends when moving from one key to another. Intervals made of pure ratios sound clearer and sweeter, but when you start stacking them up on top of each other they drift, slightly but always further and further from the original tone. Otto makes this tiny paradoxical discrepancy the driving force of his new composition.

In rag′sma, two pre-recorded string quartets start from the same place and slowly weave back and forth on these simple harmonies, with each step building from the previous note instead of from a common reference tone. One quartet inexorably rises while the other falls, albeit at a rate too small for the ear to distinguish. After about a minute, multiplication of these simple numbers means that each quartet has deviated in pitch by one ragisma, which works out to about one two-hundred-and-fiftieth of a semitone (or one-fifth of a schisma, if that helps). Can you hear a difference that small? By itself, no; in context with other pitches, yes, in mysterious ways.

What would otherwise be the same harmony can shade from sour to sweet, clear to cloudy, all on these small inflections of intonation. Here, the differences are subtle enough that the more common acoustic interference phenomena of beating and overtones are not prominent. The piece is a constant, radiant source of exotic colourations in harmony and timbre, with strings taking on a buzzing quality before resolving into a singing tone, minor key shadings on warped major triads, pitches that seem to arise from nowhere. The spiral-like movements around the tuning chart (suggested in the cover art) reflect the structure and effect of the piece: too slow and steady to make you dizzy, but a process of constant change that never lets you pin down exactly where you are until the ride is over.

This album contains two versions of rag′sma, the two-quartet recording described above and an alternate version where a third quartet plays live over the other two. The live quartet plays harmonic tropes, fading in and out with chords that augment and transition between each turn in the spiral. While denser in texture and harmony, the third quartet’s higher register brightens the overall sound and gives more extroverted colouration to the piece. The album sequences this version first, preparing the ear to appreciate the relatively more sombre two-quartet version. Oddly enough, it’s hard to immediately reconcile that the second track is made from the same basic foundation as the first, such is the effect that a small increment in tuning can have on the whole.

I didn’t see anything in the sleeve notes if someone worked out how many different pitches are played in this piece (I’m remembering how Ben Johnston’s 7th String Quartet took a simple process that branched out into 1027 tones), or if the constant shifting rendered the exercise moot. If you’re wondering how on earth a string quartet could play this stuff, it’s to do with Otto being first violinist and co-founder of the JACK Quartet. This appears to be his first major composition recording, after having nurtured an interest in alternative tunings since being a student. There’s no mention here of what, if any, technical support was needed by the quartet to get the right intonation and synchronisation between the three recordings. Having heard them play Rădulescu’s Fifth at Wigmore Hall some years back like it wasn’t a big deal, it could well be that this perfomance is another outcome of years working together on projects like this and other spectralist works made from harmonic overtones. Their playing here maintains a baroque serenity, somewhere between a consort of viols and a glass armonica. I presume it would be a challenge for others to attempt it.

Each mix has been spatialised in its own way. It’s getting released on vinyl and as download, not sure if a binaural or multichannel digital file will be made available.