Some Basic ii-V-I Substitutions

I guess everybody knows the ii-V-I is the most important chord sequence in jazz. A lot of folks also know that there are about a million ways to play it that aren't, in fact, ii-V-I at all. So what's going on with that?

In Great American Songbook tunes, the ii-V-I usually feels to me like you just teleported to a spot that's close to where you want to go, and you dash straight there. You start off in motion. When you arrive at your destination, the I, you often just teleport somewhere else to dash towards another, different I.

This feels to me very different from a lot of classical and pop music where you start "at home" and only then move away, expecting to return home again, perhaps at the top of the form via a "turnaround". Yes, we have turnarounds in jazz too but they often don't take you home but rather to whatever chord starts Bar 1. For instance, if the first four bars are a ii-V-I to C major, the first chord is Dm7 and the turnaround at the end will often resolve to D. This seems to me to implicate the turnaround in the ii-V-I that opens the tune rather than making for a resolution on Bar 1. Maybe that's just my way of thinking of it but I think it does help when navigating changes.

In fact, many of those tunes are made almost entirely of ii-V-I sequences. And the key thing is that the specific chords -- the ii, the V and the I -- don't matter at all. All of them can be changed and frequently are. They can be changed to almost anything. What matters is that movement: starting at a distance from where you want to go, raising the tension as you make the journey and resolving it, albeit briefly, when you arrive. It would be better not to call it a ii-V-I at all.

Anyway, this post is mostly a big list of well-known ways to play this movement, which you can choose from whenever you see a ii-V-I written out explicitly on a lead sheet. Of course, not all will sound equally good in the context on a song, a melody etc, so you do still have to listen (sorry).

1. The Basic Version

I'll use the example in C major over four bars -- here's the basic ii-V-I you see on all the lead sheets:

Dm7     | G7     | CΔ     | CΔ      |

But why is this so successful? One answer comes from looking at the shells of these chords. The shell is just the 3 and 7, the notes that most firmly set the sound of the chord; if a bass player plays the roots, it's quite common to only play these notes as a way to state the harmony in a very sparse way, leaving lots of room for other things to happen.

The shells are [F, C], [F, B] and [E, B]. Notice how the V7's shell, [F, B], shares its F with the previous shell and its B with the next one. What's more, the notes that change each move down by a single semitone. This is considered very strong voice-leading, and that will be a theme of all the other variations.

There are a few very common ways to vary individual chords in this basic pattern. I won't always mention these below but they're always fair game to try out.

You can play the dominant 7 instead of the minor 7. In that case the shells become The shells are [F#, C], [F, B] and [E, B]. This breaks the idea of the chords "holding hands" via a shared note but gives us a very strong chromatic movement in both notes between D7 and G7. Dominant chords moving in fourths like this can be chained almost as long as you like: D7-G7-C7-F7-Bb7-...

You can play an augmented triad instead of the dominant chord. G+ is [G, B, D#]; it doesn't really have a shell but it has two notes besides the root, [B, D#]. The B of course keeps the tie to the previous chord but the D# provides a bluesy resolution to the third of C major: the whole sequence is [F, C], [B, D#], [E, B]. You might find it easier to "visualize" G+ as B+, i.e. the augmented triad immediately below the CΔ you're trying to get to.

You can also replace a dominant chord with the diminished seventh chord a semitone above it. This is Ab°, which is [Ab, B, D, F]. As you can see it shares the [B, F] shell with G7, which is primarily why it works. Again, you might prefer to think of this as B°. The only problem with this is that the Ab doesn't really go anywhere and the D echoes the D in the bass of the previous chord, which can be a bit weak. This idea will work better with some of the variations we consider next.

We can also mess with the I chord a little. It's very common to replace the first bar of I with I°, which prolongs the tension and thus delays (and perhaps sweetens) the final resolution. This needs a bit of discretion as it can sound very crunchy and might come off like a mistake so find voicings you like before committing to it.

It's also common (and less daring) to replace the I with the iii (Em7 in the key of C). You can still play the root of the I in the bass if you like. Em7 is E-G-B-D, which is just the shell of C plus the fifth (for extra stability) and the ninth (a pretty note). So you can think of this as just a voicing decision or play the E in the bass and lean into it. This can be useful when you want to resolve but not too much; you're really on your way somewhere else.

Note that this post is about major ii-V-Is but similar ideas work with the minor version, although they can be a bit more sensitive. Be particularly careful with chords that include the third of the I (e.g. the note E in the key of C) and remember the ii is usually played as a m7b5 since the natural 5 on the V (A in the key of C) will tend to impart a Dorian quality to the whole progression.

2. Tritone Substitution

This well-known technique involves substituting a chord for one that's a tritone away -- a flat fifth, or half an octave. You can do this with the ii, the V or both. First the titone sub on the V only:

Dm7     | Db7     | CΔ     | CΔ      |

The shells are [F, C], [B, F] and [E, B] -- the only difference is that the 3 and 7 in the dominant chord have swapped over. What's changed is the bassline: rather than the double-leaping D-G-C movement we have the chromatic "walkdown" D-Db-C.

Now we take the same thing and move the ii by a tritone as well, so we're playing a ii-V in the key of Gb but resolving to the I in the key of C:

Abm7     | Db7     | CΔ     | CΔ      |

The shells are [B, Gb], [B, F] and [E, B] -- this time the bassline gets a single leap (Ab-Db-C) B is held throughout and the other notes creep down chromatically Gb-F-E, another strong motion.

Finally, here's the version with the tritone substitution on the ii only:

Abm7     | G7     | CΔ     | CΔ      |

The shells are again [B, Gb], [B, F] and [E, B] and the bassline's leap happens after the chromatic step (Ab-G7-C). It also allows you to do a slippery ii-V-I by playing Abm7-Ab°-CΔ. This can be prolonged using the I° substitution, which is the same as vi°, into Abm7-Ab°-A°-CΔ.

There's nothing to stop you using both the "vanilla" and tritone versions of the ii-V at double speed, which increases harmonic density:

Dm7   G7     | Abm7   Db7     | CΔ     | CΔ      |

This will be a theme of some of the later examples -- it gives you something more active to play when you need that.

3. The Backdoor ii-V-I

This phrase "borrows" the ii-V from a completely different key, a minor third above the actual key. So in C, we play a ii-V to Eb but then resolve it to C.

Fm7     | Bb7     | CΔ     | CΔ      |

The way I tend to "find" this is to jump to the fourth of the target chord (F in this case). This phrase shouldn't really work if we look at the shells: [Ab, Eb], [D, Ab], [E, B]. Of course the first two chords are nicely connected together, they're a ii-V. But the second and third chords really seem to have no strong connection.

The idea that made sense to me is the one mentioned in this post by Anton Schwartz, which includes a long list of standards that include this version of the ii-V explicitly. The idea is that this is actually a tritone substitution of the ii-V to the relative minor (A in this case), and Am7 contains all the same notes as C6. The resolution also voice-leads very nicely into Em7 as a substitute for CΔ

Usually on a ii-V, we can get fancy with the V chord and introduce a lot of dissonance. Another thing Anton Schwartz mentions is that you might not want to do that here. When I see this one I treat it with a bit of caution and try to play it pretty, not crunchy; we'll see a more fancy variation later.

4. iii-VI-ii-V

This is an old one, and I prefer to think of it as "approaching the ii-V from a tone above":

Em7   A7     | Dm7   G7     | CΔ     | CΔ      |

It works because the A7 is the V of the Dm7, so the shells line up quite nicely: [G, D], [G, C#], [F, C], [F, B], [E, B]. The only wrinkle is the resolution A7-Dm7, where the G moving to F is somewhat weak; replacing Dm7 with D7 is a nice solution.

You can expand this further by putting the usual ii-V at the start, delaying the resolution by a bar:

Dm7   G7     | Em7   A7     | Dm7   G7     | CΔ      |

This can be heard in many swing-era tunes; in an even more expanded version it accounts for the entire A section of "Satin Doll" (with a tritone sub on the final ii-V).

5. Side-Slips: "Stablemates" and "Moment's Notice"

The opening of John Coltrane's tune "Stablemates" uses an interesting extension of the ii-V by approaching it from a semitone above:

Ebm7   Ab7     | Dm7   G7     | CΔ     | CΔ      |

I think of this as a variation on the iii-VI-ii-V version, just shifting up by a semitone instead of a tone. Although it looks outlandish the shells go [Gb, Db], [C, Gb], [F, C], [F, B], [E, B] -- in every case one note is shared, the other moves by a semitone.

A similar-looking but actually quite different idea occurs a few times in another Coltrane tune, "Moment's Notice". The first ii-V is shifted by a semitone below instead:

Dbm7   Gb7     | Dm7   G7     | CΔ     | CΔ      |

Again the shells tell the story: [Fb, B], [Bb, Fb], [F, C], [F, B], [E, B]. The big difference here is the movement Gb7-Dm7, which has that somewhat weak movement by a whole tone from Bb to C. Unlike with the ii-VI-ii-V, though, converting the Dm7 to a D7 only makes matters "worse". I say "worse" in quotes because really I think this non-chromatic movement is characteristic of this variation, and part of what makes it sound so interesting. Try playing some of the middle chords as augmented triads (or 7#5s) to really emphasize that whole-tone movement.

Hat tip to this Matt Warnock article, which is where I saw these two put side-by-side for the first time.

Pushing something off by a semitone, up or down, is a common technique in jazz and works way more often than it deserves to. In soloing it's referred to as "side-slipping", and often when you side-slip you resolve the phrase back to something in the "correct" key to tip the listeners off that you know what you're doing (and, you know, resolve the tension). I feel like these two versions of ii-V-I are like the harmonic blueprint for that.

6. Resolving by a Major Third

Let's go back to the backdoor ii-V-I, which in C is Fm7-Bb7-CΔ. I mentioned that this can be thought of as the tritone sub version of a ii-V-I to Am: Fm7-Bb7-Am. What if we "undid" the tritone sub, i.e. replace the ii and V in the backdoor progression with chords a tritone away? We'd get this:

Bm7     | E7     | CΔ     | CΔ      |

This is something new: a resolution down a major third, from E7 to C. The shells don't voice lead particularly smoothly but it still works, I think for the same reason the original backdoor progression did: the E7 "wants" to resolve to A minor, which is the relative minor of C and hence very closely related to it. As with the backdoor progression, the actual resolution is a fairly mild surprise.

7. Coltrane Changes ("Countdown")

Coltrane's "Giant Steps" is famous for its movement by major thirds -- in the key of C that would be moving down through a C augmented triad, G#-E-C. The idea of the Countdown substitution is to play a sequence of V-Is to each of those key centres in turn. We start with the usual Dm7 but then jump into the sequence by moving up a semitone, then follow the cycle of major thirds down the augmented triad until we get home:

Dm7   D#7   | AbΔ   B7   | EΔ   G7  | CΔ      |

The harmonic rhythm of this, to my ear, is "a step and a jump" -- each dominant chord resolves to its tonic by step, but then you jump to the next dominant chord. For example, AbΔ to B7 if a shell movement of [C G] to [D# E] -- that's the "jump".

This is a very different beast from what we've seen before and it can seem intimidating, but I think visualizing the major chords as a descending augmented triad really helps. There's an element of "timing" to getting this right -- you have to start with the first V7 halfway through the first bar, and anchoring yourself by putting the normal ii7 before it, then stepping up a semitone is a prompt I find helpful in making sure I don't follow the wrong cycle and end up somewhere I didn't mean to.

It's perfectly possible to imagine going up from the third of the augmented triad instead. I don't know whether this is ever done in legit jazz circles but it sounds pretty sweet to me:

Dm7   B7   | EΔ   D#7   | AbΔ   G7  | CΔ      |

Different steps and jumps but essentially the same dance.

So there you have it, a collection of very standard ii-V-I substitutions you can find anywhere else on the web. I've put this together partly for my own reference (I'm still finding my way around piano harmony) and partly because I'd like to use it as a basis for a series of posts for more "advanced" and probably less jazzy variations on the same idea.