Marvel chords are essentially tempered dyadic chords tempered by the marvel comma, 225/224. The marvel triad, aka marvel augmented triad, or septimal augmented triad, is a marvel chord which in close position consists of two major thirds of approximately 5/4 and a supermajor third of approximately 9/7, or in other words a 5/4-5/4-9/7 chord, which closes at the octave since the marvel comma, 225/224, is tempered out. In meantone this triad consists of two major thirds and a diminished fourth, the classic augmented triad of the meantone era. It can also be described as a marvel-tempered version of a 1-5/4-14/9 chord.
There are three 9-odd-limit marvel triads:
- The aforementioned marvel augmented triad;
- 5/4-9/8-10/7 and its inversion, temperings of 1-5/4-7/5 and 1-5/4-16/9.
There are six 9-odd-limit marvel tetrads:
- 5/4-9/8-10/9-9/7 and its inversion, temperings of 1-5/4-7/5-14/9 and 1-5/4-8/5-16/9;
- 5/4-9/8-8/7-5/4 and its inversion, temperings of 1-9/8-7/5-7/4 and 1-5/4-7/5-8/5;
- 5/4-9/8-5/4-8/7, the tempering of 1-5/4-7/5-7/4;
- 9/8-10/9-9/8-10/7, the tempering of 1-9/8-5/4-7/5.
The first four tetrads contain the marvel augmented triad.
There are two 9-odd-limit marvel pentads:
- 9/8-10/9-9/8-5/4-8/7 and its inverse, which are the temperings of 1-9/8-5/4-7/5-7/4 and 1-9/8-5/4-7/5-8/5.
One notable 15-odd-limit tetrad is 1-4/3-3/2-15/8 which has as its homonym 1-9/8-7/5-3/2.