<P> The table shows the most widely used conventional names for the intervals between the notes of a chromatic scale . A perfect unison (also known as perfect prime) is an interval formed by two identical notes . Its size is zero cents . A semitone is any interval between two adjacent notes in a chromatic scale, a whole tone is an interval spanning two semitones (for example, a major second), and a tritone is an interval spanning three tones, or six semitones (for example, an augmented fourth). Rarely, the term ditone is also used to indicate an interval spanning two whole tones (for example, a major third), or more strictly as a synonym of major third . </P> <P> Intervals with different names may span the same number of semitones, and may even have the same width . For instance, the interval from D to F ♯ is a major third, while that from D to G ♭ is a diminished fourth . However, they both span 4 semitones . If the instrument is tuned so that the 12 notes of the chromatic scale are equally spaced (as in equal temperament), these intervals also have the same width . Namely, all semitones have a width of 100 cents, and all intervals spanning 4 semitones are 400 cents wide . </P> <P> The names listed here cannot be determined by counting semitones alone . The rules to determine them are explained below . Other names, determined with different naming conventions, are listed in a separate section . Intervals smaller than one semitone (commas or microtones) and larger than one octave (compound intervals) are introduced below . </P> <Table> <Tr> <Th> Number of semitones </Th> <Th> Minor, major, or perfect intervals </Th> <Th> Short </Th> <Th> Augmented or diminished intervals </Th> <Th> Short </Th> <Th> Widely used alternative names </Th> <Th> Short </Th> <Th> Audio </Th> </Tr> <Tr> <Td> 0 </Td> <Td> Perfect unison </Td> <Td> P1 </Td> <Td> Diminished second </Td> <Td> d2 </Td> <Td> </Td> <Td> </Td> <Td> Play (help info) </Td> </Tr> <Tr> <Td> </Td> <Td> Minor second </Td> <Td> m2 </Td> <Td> Augmented unison </Td> <Td> A1 </Td> <Td> Semitone, half tone, half step </Td> <Td> </Td> <Td> Play (help info) </Td> </Tr> <Tr> <Td> </Td> <Td> Major second </Td> <Td> M2 </Td> <Td> Diminished third </Td> <Td> d3 </Td> <Td> Tone, whole tone, whole step </Td> <Td> </Td> <Td> Play (help info) </Td> </Tr> <Tr> <Td> </Td> <Td> Minor third </Td> <Td> m3 </Td> <Td> Augmented second </Td> <Td> A2 </Td> <Td> </Td> <Td> </Td> <Td> Play (help info) </Td> </Tr> <Tr> <Td> </Td> <Td> Major third </Td> <Td> M3 </Td> <Td> Diminished fourth </Td> <Td> d4 </Td> <Td> </Td> <Td> </Td> <Td> Play (help info) </Td> </Tr> <Tr> <Td> 5 </Td> <Td> Perfect fourth </Td> <Td> P4 </Td> <Td> Augmented third </Td> <Td> A3 </Td> <Td> </Td> <Td> </Td> <Td> Play (help info) </Td> </Tr> <Tr> <Td> 6 </Td> <Td> </Td> <Td> </Td> <Td> Diminished fifth </Td> <Td> d5 </Td> <Td> Tritone </Td> <Td> TT </Td> <Td> Play (help info) </Td> </Tr> <Tr> <Td> Augmented fourth </Td> <Td> A4 </Td> </Tr> <Tr> <Td> 7 </Td> <Td> Perfect fifth </Td> <Td> P5 </Td> <Td> Diminished sixth </Td> <Td> d6 </Td> <Td> </Td> <Td> </Td> <Td> Play (help info) </Td> </Tr> <Tr> <Td> 8 </Td> <Td> Minor sixth </Td> <Td> m6 </Td> <Td> Augmented fifth </Td> <Td> A5 </Td> <Td> </Td> <Td> </Td> <Td> Play (help info) </Td> </Tr> <Tr> <Td> 9 </Td> <Td> Major sixth </Td> <Td> M6 </Td> <Td> Diminished seventh </Td> <Td> d7 </Td> <Td> </Td> <Td> </Td> <Td> Play (help info) </Td> </Tr> <Tr> <Td> 10 </Td> <Td> Minor seventh </Td> <Td> m7 </Td> <Td> Augmented sixth </Td> <Td> A6 </Td> <Td> </Td> <Td> </Td> <Td> Play (help info) </Td> </Tr> <Tr> <Td> 11 </Td> <Td> Major seventh </Td> <Td> M7 </Td> <Td> Diminished octave </Td> <Td> d8 </Td> <Td> </Td> <Td> </Td> <Td> Play (help info) </Td> </Tr> <Tr> <Td> 12 </Td> <Td> Perfect octave </Td> <Td> P8 </Td> <Td> Augmented seventh </Td> <Td> A7 </Td> <Td> </Td> <Td> </Td> <Td> Play (help info) </Td> </Tr> </Table>

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