25/21

Interval information

Ratio	25/21
Factorization	3-1 × 52 × 7-1
Monzo	[0 -1 2 -1⟩
Size in cents	301.8465¢
Name	quasi-tempered minor third
Color name	ryy2, ruyoyo 2nd
FJS name	[math]\displaystyle{ \text{A2}^{5,5}_{7} }[/math]
Special properties	reduced
Tenney norm (log2 nd)	9.03617
Weil norm (log2 max(n, d))	9.28771
Wilson norm (sopfr(nd))	20
[sound info]
Open this interval in xen-calc

25/21, the quasi-tempered minor third, is the interval between 6/5 and 10/7, and also 7/5 and 5/3. It is 225/224 sharp of 32/27, 126/125 flat of 6/5, and tempering out 126/125 makes the 1–6/5–10/7 triad into a diminished triad where two minor thirds make up a tritone. It is extremely close to 3 steps of 12edo (300 cents).

25/21 is also an important interval in the Bohlen–Pierce scale, where it represents a "BP whole tone", i.e. the large step in the Lambda scale.

Approximation

Edo approximations for 25/21 (301.85 ¢)
≤ 80edo, relative error ≤ 10%

Edo	Step size	Cents (¢)	Absolute error (¢)	Relative error (%)
4	1\4	300.00	-1.85	-0.62
8	2\8	300.00	-1.85	-1.23
12	3\12	300.00	-1.85	-1.85
16	4\16	300.00	-1.85	-2.46
20	5\20	300.00	-1.85	-3.08
24	6\24	300.00	-1.85	-3.69
28	7\28	300.00	-1.85	-4.31
32	8\32	300.00	-1.85	-4.92
36	9\36	300.00	-1.85	-5.54
40	10\40	300.00	-1.85	-6.16
44	11\44	300.00	-1.85	-6.77
48	12\48	300.00	-1.85	-7.39
52	13\52	300.00	-1.85	-8.00
56	14\56	300.00	-1.85	-8.62
60	15\60	300.00	-1.85	-9.23
64	16\64	300.00	-1.85	-9.85

See also

• 42/25 – its octave complement
• 63/50 – its fifth complement
• 28/25 – its fourth complement
• Gallery of just intervals
• File:Ji-25-21-csound-foscil-220hz.mp3 - another sound example