Source: wikibot/all-interval-tetrachord

= All-interval tetrachord
{wiki=All-interval_tetrachord}

An all-interval tetrachord is a specific arrangement of four distinct musical pitches that encompasses all possible intervals between the notes. In Western music theory, the intervals between four notes can generate a variety of relationships, and an all-interval tetrachord is designed to include each of the six possible intervals (major second, minor third, major third, perfect fourth, perfect fifth, and minor sixth) exactly once.