Aureusmic chords

Aureusmic chords are essentially tempered dyadic chords tempered by the aureusma, 1445/1444.

The most typical aureusmic triad is a palindrome in the 2.5.17.19 subgroup 19-odd-limit since it identifies 5/4 by a stack of two 19/17's:

• 1-19/17-5/4 with steps 19/17-19/17-8/5.

There is an inversely related pair which is even more squeezed:

• 1-17/16-19/17 with steps 17/16-20/19-8/5, and its inverse
• 1-20/19-19/17 with steps 20/19-17/16-8/5.

They can be extended to the following inversely related tetrads, all of which seem to be based largely on a sort of secundal harmony:

• 1-19/17-19/16-5/4 with steps 19/17-17/16-20/19-8/5, and its inverse
• 1-20/19-19/17-5/4 with steps 20/19-17/16-19/17-8/5;
• 1-19/17-20/17-5/4 with steps 19/17-20/19-17/16-8/5, and its inverse
• 1-17/16-19/17-5/4 with steps 17/16-20/19-19/17-8/5.

Then there are two inversely related pentads:

• 1-17/16-19/17-19/16-5/4 with steps 17/16-20/19-17/16-20/19-8/5, and its inverse
• 1-20/19-19/17-20/17-5/4 with steps 20/19-17/16-20/19-17/16-8/5.