Apotome ( ancient Greek ἀποτομή , section, segment ' ) denotes the Pythagorean chromatic semitone in music since ancient Greece .
Apotome (fleshcolored) and Limma
The Pythagorean diatonic semitone is that

Limma = fourth  2 whole tones with the frequency ratio cents .${\ displaystyle {\ frac {256} {243}} \, \, {\ widehat {\ approx}} \, \, 90 {,} 22}$
The Pythagorean chromatic semitone is the
 Apotome = whole tone  Limma.
Their frequency ratio is calculated in cents .
${\ displaystyle {\ frac {9} {8}}: {\ frac {256} {243}} = {\ frac {2187} {2048}} \, \, {\ widehat {\ approx}} \, \ , 113 {,} 69}$
The apotome (113.7 cents) is a Pythagorean comma (23.5 cents) larger than the limma (90.2 cents).