Half-diminished Seventh Chord

In music theory, the half-diminished seventh chord, also known as a half-diminished chord or a minor seventh flat five (m7♭5), is created by taking the root, minor third, diminished fifth and minor seventh (1, ♭3, ♭5 and ♭7) of any major scale; for example, C half-diminished is (C E♭ G♭ B♭). Its consecutive intervals are minor 3rd, minor 3rd, major 3rd. In diatonic harmony, the half-diminished chord naturally occurs on the 7th scale degree (for example, Bø7) in C major). By the same virtue, it also occurs on the second degree of natural minor (e.g. Dm7 (♭5) in C minor). It occurs as a leading-tone seventh chord in major and can be represented by the integer notation {0, 3, 6, 10}. It has been described as a "considerable instability".