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]\text{A2}^{5,5}_{7}[/math]
Special properties	reduced
Tenney height (log2 nd)	9.03617
Weil height (log2 max(n, d))	9.28771
Wilson height (sopfr(nd))	20
Harmonic entropy (Shannon, [math]\sqrt{nd}[/math])	~4.18934 bits
[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 126/125 flat of 6/5, and tempering 126/125 out 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.

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