27/16

Interval information

Ratio	27/16
Factorization	2-4 × 33
Monzo	[-4 3⟩
Size in cents	905.865¢
Names	Threerish major sixth, Pythagorean major sixth
Color name	w6, wa 6th
FJS name	[math]\displaystyle{ \text{M6} }[/math]
Special properties	reduced, reduced harmonic
Tenney norm (log2 nd)	8.75489
Weil norm (log2 max(n, d))	9.50978
Wilson norm (sopfr(nd))	17
[sound info]
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The Pythagorean major sixth, 27/16, may be reached by stacking three perfect fifths (3/2) and reducing by one octave. Compared to the more typical 5/3 - with which it is conflated in meantone - this interval is more dissonant, with a harmonic entropy level roughly on par with that of 6/5. While many musicians prefer to use 5/3 as the major sixth interval above the tonic in a diatonic context even in non-meantone settings, Aura is known to prefer this interval in those same contexts, though he still uses 5/3 as major sixth interval between certain non-tonic notes.

See also

• 32/27 – its octave complement
• Gallery of just intervals
• Pythagorean tuning