ii7bVII7

ii7bVII7 is a two-chord harmonic progression used in tonal music, consisting of a ii7 chord followed by a flat-VII dominant seventh (bVII7). In roman numeral analysis, ii7 denotes a minor seventh built on the second scale degree, while bVII7 denotes a dominant seventh built on the lowered seventh degree. The combination is commonly seen as a form of modal mixture or as a substitute or complement to more diatonic progressions, and it can function as a lead-in to the tonic.

In a major key, a typical example is in C major: ii7 is Dm7 (D-F-A-C) and bVII7 is Bb7 (Bb-D-F-Ab). These two chords share common tones such as D and F, which helps their voice-leading. The bVII7 chord borrows from the Mixolydian mode or from the parallel minor, introducing a strong dominant pull that resolves naturally to the tonic key.

Function and use: The progression provides a chromatic approach to the tonic by pairing a diatonic ii7 with a non-diatonic dominant seventh. It is often used as a backdoor cadential approach to I, though it can also precede IV or be embedded in longer progressions. It differs from a ii–V–I sequence in that there is no standard V chord within the immediate progression, though it can lead to a V area in subsequent measures.

Variants and scope: While ii7bVII7 is most commonly described in the context of major-key harmony, analogous concepts appear in minor keys and other modal contexts, where the chords may be adapted (for example, using iiø7 or other borrowed tones). The progression is found in jazz, pop, and rock idioms and is valued for its smooth voice-leading and modal color.