The Related ii Chord

A bare secondary dominant is a chord on loan from another key, aimed at a target that isn’t the tonic — but landing on it cold can feel like skipping a step. The related ii chord is the minor seventh built a fifth above that dominant, turning one borrowed chord into a miniature ii–V cell of its own. It’s the single most common way bebop players thicken a skeletal changes sheet into something with real forward motion, and it hands soloists twice the harmonic material to work with.

From One Chord to a Miniature Key

Every secondary dominant briefly tonicizes a chord that isn’t home base — A7 in the key of C major is labeled V7/ii because it wants to resolve to Dm7. Give that A7 its own related ii, and you get Em7–A7, a self-contained (ii–V)/ii: Em7 and A7 both point at D, the key being tonicized — Em7 happens to be diatonic to C as the iii chord, but in this context the ear hears it re-cast as a local ii. (Purists targeting the minor chord Dm7 often use Em7♭5 instead, since that’s the ii of D minor; in practice both work.) Written out with Roman Numeral Analysis brackets, this is how a single borrowed dominant becomes a pocket-sized key center of its own.

A7 alone = V7/ii in C major (tonicizes Dm7)
Em7 – A7 = (ii–V)/ii in C major
Turnaround C – A7 – Dm7 – G7 becomes C – Em7 – A7 – Dm7 – G7

Em7–A7 resolving to its target Dm7 makes the pocket key center audible:

Any Secondary Dominant Can Take One

This trick works on every secondary dominant in the key, not just V7/ii. The related ii always sits a perfect fifth above its dominant, matching the same down-a-fifth logic of ordinary Dominant Resolution — it’s just relocated to a new tonal neighborhood for a bar or two. In minor keys the related ii is usually half-diminished rather than a full Minor Seventh Chord, since that’s the chord that’s actually diatonic to the minor key being tonicized.

Dm7 – G7 = the home-key ii–V in C major, for comparison
Bm7 – E7 = (ii–V)/iii in C major
Gm7 – C7 = (ii–V)/IV in C major
Bm7♭5 – E7 = (ii–V)/i in A minor

Chains of Them Are Bebop’s Fingerprint

Stack several related ii–V cells back to back and you get the stepwise-descending harmony that defines “Bird changes.” The first four bars of Charlie Parker’s “Blues for Alice” (in F) are the textbook case, and that same rewrite of a plain blues is exactly what defines a Bird Blues. It’s also a close cousin of backcycling, where dominants stack in descending fifths — related ii’s just interleave a minor seventh before each stop.

Fmaj7 | Em7♭5 A7 | Dm7 G7 | Cm7 F7 | B♭7 … (Blues for Alice, bars 1–5)

The stepwise-descending root motion of that chain is easy to hear on its own:

The bridge of a rhythm-changes tune shows the interpolation happening in real time: the lead sheet prints only four bare dominants cycling in fifths (D7–G7–C7–F7 in B♭), and players routinely front each one with its related ii — a habit that also spills into the form’s many turnarounds:

Am7 – D7 (ii–V of G), Dm7 – G7 (ii–V of C), Gm7 – C7 (ii–V of F), Cm7 – F7 (ii–V of B♭)

Related ii’s Play Nice With Tritone Subs

A related ii can also front a tritone substitute instead of the “real” dominant — Abm7–Db7 stepping in for Am7–D7 is common Chord Substitution practice, since Db7 shares the same tritone as the Dominant Seventh Chord it replaces. The net effect, in any of these cases, is a faster Harmonic Rhythm — one bar of dominant becomes two chords — while the actual resolution gets delayed just long enough to feel earned rather than abrupt — and experienced improvisers will often play the related ii even when a chart only prints the bare dominant, because the two chords function as one unit in their ears regardless of what’s notated. The bridge of All the Things You Are leans on this same tonicize-then-resolve logic, cycling through secondary keys the ear reads as a string of little ii–V’s rather than one long modulation.

♫ Listen

Charlie Parker — “Confirmation” (Verve studio recording, 1953): the descending ii–V cells in the first four bars of the head are a related-ii clinic — track how each pair resolves down a fifth before the next tonicization begins.
Charlie Parker — “Blues for Alice” (Verve, 1951): the F-major blues head reroutes the standard changes through the Em7♭5–A7 chain above; listen for how it makes a familiar form feel freshly harmonized.
Bill Evans Trio — “Autumn Leaves” (Portrait in Jazz, 1959): Evans fills in related ii’s under the Autumn Leaves changes even where the lead sheet shows a bare dominant — a good example of the “play the cell, not the chart” habit.