Challenge: Stack your 12-tone solutions!
Why limit ourselves to three-note chords? We can stack harmonic solutions to create more sophisticated sounds.
Step 1. Devise and select two solutions for four triads. There are no rules past this point, and we may select any two solutions – one simple idea is to use the same basic structure (for example, tritone-separated triad pairs), but with two separate ‘root notes’. For example:
| C major | D minor | Gb major | Ab minor |
| C | D | Gb | Ab |
| E | F | Bb | B |
| G | A | Db | Eb |
And…
| G major | A minor | Db major | Eb minor |
| G | A | Db | Eb |
| B | C | F | Gb |
| D | E | Ab | Bb |
Step 2. Stack or overlay these solutions vertically to create interesting extended harmonies and polychords. Of course, stacking triads that share one or more pitches (such as CEG and GBD) will create a disproportionate representation of some pitches over others in performance. But the aim is to create interesting and useful musical sounds – we are not obliged to measure our success by whether every pitch is equally weighted in the end result.
| C major 9 | D minor 9 | Gb major 9 | Ab minor 9 |
| C | D | Gb | Ab |
| E | F | Bb | B |
| G | A | Db | Eb |
| B | C | F | Gb |
| D | E | Ab | Bb |
Step 3. Play!
Eitan Muir 