In
tuning systems using
just intonation, such as
5-limit tuning, in which major seconds occur in two different sizes, the wider of them is called a
major tone or
greater tone, and the narrower
minor tone or,
lesser tone. The difference in size between a major tone and a minor tone is equal to one
syntonic comma (about 21.51 cents). The major tone is the 9:8 interval , and it is an approximation thereof in other tuning systems, while the minor tone is the 10:9 ratio The 9:8 major tone arises in the C major scale between C and D, F and G, and A and B. This 9:8 interval was named
epogdoon (meaning 'one eighth in addition') by the Pythagoreans. Notice that in these tuning systems, a third kind of whole tone, even wider than the major tone, exists. This interval of two semitones, with ratio 256:225, is simply called the
diminished third (for further details, see ). Some equal temperaments also produce major seconds of two different sizes, called
greater and
lesser tones (or
major and
minor tones). For instance, this is true for
15-ET,
22-ET,
34-ET,
41-ET,
53-ET, and
72-ET. Conversely, in
twelve-tone equal temperament,
Pythagorean tuning, and
meantone temperament (including
19-ET and
31-ET) all major seconds have the same size, so there cannot be a distinction between a greater and a lesser tone. In any system where there is only one size of major second, the terms
greater and
lesser tone (or
major and
minor tone) are rarely used with a different meaning. Namely, they are used to indicate the two distinct kinds of whole tone, more commonly and more appropriately called
major second (M2) and
diminished third (d3). Similarly,
major semitones and
minor semitones are more often and more appropriately referred to as
minor seconds (m2) and
augmented unisons (A1), or
diatonic and
chromatic semitones. Unlike most uses of the terms
major and
minor, these intervals span the
same number of semitones. They both span 2 semitones, while, for example, a
major third (4 semitones) and
minor third (3 semitones) differ by one semitone. Thus, to avoid ambiguity, it is preferable to call them
greater tone and
lesser tone (see also greater and lesser
diesis). Two major tones equal a
ditone. ==
Epogdoon==