Topic summary
Minor tone
Extracted from the Wikipedia article Major second.
Major and minor tones
The harmonic series yields two different sizes of whole tones. The first is known as the "greater tone". Its 9:8 frequency ratio is about 4 cents larger than the whole tone of equal temperament. The "lesser tone" is in a 10:9 ratio and is 18 cents smaller. Their size differs by exactly one syntonic comma (81:80, or about 21.5 cents). Some equal temperaments, such as 15-ET and 22-ET, also distinguish between a greater and a lesser tone.