The 24-Tone Equal Tempered scale (aka quarter-tone or 24-TET scale) contains all the notes of the standard 12-note scale, but adds 12 more notes in between. The additional pitches open up a huge variety of new harmonic possibilities, allowing for both traditional harmonies and ‘alien’ ones.
This allows Lennox to freely move between familiar scales and chords and unfamiliar ones, creating harmonies that may seem strange or even disorienting to some musicians.
Here’s what Lennox has to say about it:
“The work is written in 24-TET (24 notes per octave), but I’m treating it as two stacked layers of 12-TET (12-TET is the foundation of Western harmony), each layer 1/4 tone apart. Hence ‘Parallel-12’.
Parallel-12 harmony is something I’ve been developing alongside full 24-tone harmony. I’ll upload a few pieces in this harmonic system in the near future. Some of the changes in Parallel-12 can be achingly beautiful.
The entire system of Parallel-12 is an unexplored landscape. But that’s partly because I’m developing it.
There’s so much to explore in the world of harmony. Vast, unexplored continents, I’d say. Sometimes it’s good to stay at home; at other times it is great to pack supplies and head off into the wilderness.
In Parallel-12, all chords sound ‘musical’ – but the changes between them can sound very, very unusual. In fact, the changes of this piece haven’t been heard before.
There are numerous Parallel-12 shifts throughout: the changes at the sudden filter shifts should be obvious (and some will be less so).
This was written in MIDI (well, written in the mind, then inputted in MIDI), which is a small nightmare in Parallel-12 (i.e the MIDI notes don’t correspond to the actual pitches, so the process takes a very long time). MIDI sent to the synth, freeing up the hands to play with the filters etc (plus in order to physically play this, I’d need more than 88 keys. And even if I did play it, I’d have no hands left to adjust the filter etc! Catch-22).
Time signature is 36/16 (or you could think 4 groups of 9/16).”