27/10
| Ratio | 27/10 |
| Monzo | |-1 3 -1> |
| Size | 1719.5512887313 ¢ |
| Name(s) | large minor eleventh |
In 5-limit Just Intonation, 27/10 is a large minor eleventh of about 1719.6¢. It is a tritave inverse of a superparticular interval, as you can find it in the harmonic series between the 27th and the 10th overtones. It is one of two essential minor elevenths in the 5-limit; the other one is 8/3 (about 1698.0¢), which is 81/80 (about 21.5¢) lower than 27/10. 27/10 is a tritave-reduced undertone, and it is further from 12edo's single minor eleventh of 1700¢. Thus, 8/3 is more familiar and less difficult to tune by ear than 27/10.
The last three notes of a tritave JI major scale -- 12/5, 8/3, 3/1 -- move by a step of 10/9 followed by a step of 9/8 (or alternatively 12/5, 27/10, 3/1 -- move by a step of 9/8 followed by a step of 10/9). In systems where 81/80 is tempered out (in 12edo, 19edo, 31edo and other meantone systems) that distinction is lost and this sounds like two equal-sized steps. In strict JI, the difference is tiny and hard to notice at first.
- See also Gallery of Just Intervals