The 10 Chord Toolkit: Part 2

Chord 7: The ii (Minor Two)

The ii chord is the chord built on the second degree of the scale. In C, that’s D minor. It’s a gentle, slightly melancholy chord that naturally wants to move to the V chord. The progression ii → V → I (Dm → G7 → C) is one of the most important in all of music — it shows up everywhere from jazz standards to pop ballads to gospel.

The ii chord lives in the subdominant family — sometimes called the predominant family, because it tends to show up right before the dominant chord. It does a similar job to the IV chord (both contain the fourth scale degree), but it has a softer, darker quality. Think of ii as the IV chord’s introspective cousin.

Chord 8: The iii (Minor Three)

The iii chord — E minor in the key of C — is the quietest member of the toolkit. It shares two notes with the I chord (E and G are both in C major) and two notes with the V chord (E and B are both in G major), so it can lean either way. It’s a connector — a chord that bridges tonic and dominant territory without committing to either.

You don’t hear iii in isolation very often, but it shows up in longer progressions where the harmony needs a stepping stone. It’s also the diatonic version of the V/vi — same root (E), but minor instead of major. The iii chord stays inside the key; the V/vi (E7) steps outside it. That distinction matters.

Chord 9: The ♭VII (Flat Seven)

The ♭VII — B♭ major in the key of C — doesn’t belong to the C major scale. That B♭ note isn’t in the key. So where does it come from?

One way to think about it: just like D7 → G is the “five of five” (a secondary dominant chain), B♭ → F is the “four of four” — a cascading plagal cadence. B♭ is the IV of F, and F is the IV of C. So when you hear B♭ → F → C, you’re hearing a chain of subdominant resolutions rolling toward home.

The ♭VII has a distinctive, wide-open sound. It doesn’t pull toward the tonic the way V does — instead, it kind of floats back to it. You hear it constantly in rock, pop, and film music. Think of the ♭VII → I progression as a door swinging open rather than a magnet snapping shut. (Later, in the chapter on borrowed chords, we’ll revisit this chord from a different angle — and that’s okay. One of the beautiful things about music theory is that more than one explanation can be true.)

I → ♭VII → IV → I on the Harmony Wheel — hear that open, floating quality.

Chord 10: The iv (Minor Four)

Full disclosure: the “10 Chord Toolkit” could have been 9 or 11 — those numbers just didn’t have the same ring. This last slot had a few contenders, but we chose the iv chord — F minor in the key of C — because it’s particularly common and gives you some interesting places to go.

The regular IV chord (F major) has an A in it; the iv chord (F minor) has an A♭. That one lowered note — the minor third of the chord — gives it a completely different emotional weight. It’s darker, more bittersweet, more final than the regular IV.

The iv → I progression is the minor plagal cadence — a variation of IV → I, but with a heavier, more dramatic quality. You hear it at the end of songs, at emotional peaks, at moments when the music needs to say something profound without screaming it. And here’s something worth noting: Dm → Am works the same way — it’s a plagal cadence in the relative minor. Cadences direct you to a key center more than a key quality. Whether you land on major or minor, the pull is the same.

The Complete Toolkit

Here it is — all ten:

Ten chords. Six are diatonic (they live inside the major scale). Two are secondary dominants (they borrow the V-chord pull to aim at non-tonic targets). Two are borrowed from the parallel minor (modal interchange).

Between them, these ten chords cover an enormous range of music. Not all of it — we’ll encounter more exotic harmony later — but enough to analyze, understand, and talk about the vast majority of what you’ll hear.

The Perfect/Plagal Spectrum

One useful way to think about these ten chords: arrange them on a spectrum.

On one end, you have the perfect cadence side — chords that pull toward the tonic with the force of dominant resolution (V, V7, V/vi, V/V). These are the chords with leading tones, with wallets, with urgency.

On the other end, you have the plagal cadence side — chords that drift toward the tonic with the gentleness of subdominant motion (IV, ii, iv). These are the sighs, the “amens,” the soft landings.

In the middle, you have chords that could go either way depending on context (vi, iii, ♭VII). The vi leans toward the tonic side but can be pulled toward the dominant. The ♭VII floats. The iii connects.

This spectrum isn’t something you need to memorize. It’s a feeling — and over time, as you listen to more music with these ten chords in mind, you’ll start to sense where each one sits without thinking about it.

Descending Bass Lines

Now that you have the full toolkit, listen for this: songs where the bass note walks steadily downward, one step at a time — chromatically. This is the descending bass line — one of the oldest and most emotionally effective devices in music.

The bass line: C → B → B♭ → A → A♭ → G → F# → F → C

Over that descending bass, the chords go:

C → G/B → B♭ → F/A → Fm/A♭ → C/G → D/F# → G/F → C

Look at what’s happening here. The bass walks down chromatically — every note one half step lower than the last — while the chords above it draw from the toolkit. The G/B is just a V chord with B in the bass (an inversion). The B♭ is the ♭VII. The F/A is a IV inversion. The Fm/A♭ is the borrowed iv in inversion. C/G is the I chord with G in the bass. D/F# is the V/V — a secondary dominant in inversion. And G/F is V7 with its seventh in the bass, leaning hard toward the final C.

Almost every chord comes from the toolkit. The magic is that inversions let you rearrange those chords so the bass notes line up into a smooth chromatic line — voice leading at work, even before we’ve officially talked about it.

Descending bass lines work because they combine smooth, stepwise motion with harmonic variety. The bass walks down, and the chords change above it — sometimes staying in the key, sometimes borrowing from outside. Listen for them. They’re everywhere — from Adele to the Beatles to Bach.

What’s Next

You have the toolkit. Now what? In the next chapter, we’re going to zoom out and talk about song form — how songs are organized into sections, why that organization matters, and how to start hearing the structure beneath the surface. The chords are the vocabulary. Form is the grammar.