12:15:18:20

The just added sixth chord is a 5-prime-limit, 9-odd-limit chord of just intonation which is an "ASS", or anomalous saturated suspension. In close position, it is 12:15:18:20 (1⁄1–5⁄4–3⁄2–5⁄3), with steps 5/4, 6/5 and 10/9. Its inversion is 10:12:15:18 (1⁄1–6⁄5–3⁄2–9⁄5), in which form it can be called a just minor seventh chord.