Seventh Chord(redirected from Delta chord)
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a chord consisting of four tones that are separated by thirds.
The main type of seventh chord has the root in the bass. Inversions of the seventh chord are formed by placing other tones in the bass. The first inversion, which has the third in the bass, is called the Quintsextakkord. The second inversion, which is known as the Terzquartakkord, has the fifth in the bass. The third inversion, which has the second in the bass, is called the sekundakkord. Depending on their tonal makeup, seventh chords are categorized as major or minor. In major seventh chords, the tones are situated at intervals of a third, and the interval of a major seventh is formed between the root and the top note. In minor seventh chords, the bass and top tones form a minor seventh. A seventh chord consisting of three minor thirds is called a diminished seventh chord. Among the most commonly used seventh chords are the dominant and subdominant chords. The most important of these are the dominant seventh chord (on the fifth degree of the scale), its inversions, and the leading seventh chords (minor, on the seventh degree of the natural major scale, and diminished, on the seventh degree of the harmonic major and minor scales). The seventh chord on the second degree, which represents the subdominant function, is also very important, especially in its first inversion, a Quintsextakkord with the subdominant in the bass.