Lesson 05 · Harmony · Bass

Chords & the Bassline That Fits

What a progression actually is, ten you can copy in A minor, and the rule that makes the bass lock to both the kick and the chords.

Device: Circuit Tracks (Synth 2 chords, Synth 1 bass) Time: ~45 min (timed) You'll make: a chord loop + a locked bassline Prereq: L1 recipe; key of A minor

In L1 you played one chord change — Am → F — and a root-note bass. That worked, but you couldn't say why, or build the next one yourself. This lesson fixes that. You'll get the small set of chords A minor actually contains, a library of ten progressions to copy (Roman numerals + the literal A-minor chords + every note spelled out), and the matching rule that ties a bassline to both the chords and the kick. Same philosophy as the drum library: copy good ones, learn why they work, build a vocabulary.

What a chord progression is (mechanism, three layers)

1 — A chord is stacked thirds. Take a scale note (the root), skip one, take the next, skip one, take the next: root + 3rd + 5th = a triad. "Skip-a-note" is the entire rule. Stack one more third and you get a 4-note 7th chord (§5).

2 — The scale decides each chord's quality. Depending on which note you start on, the thirds come out major or minor, so a single scale hands you a fixed set of chord qualities. You don't choose — you read them off the scale (§1).

3 — A progression is an ordered sequence that moves through tension and release. Some chords feel like home (rest), others like leaving or pulling back. Ordering them is routing a signal: set up tension, resolve it. In a minor key, home is the i chord (Am).

1The chords A minor actually contains

A natural minor is all white keys: A B C D E F G. Build a triad on each note by stacking thirds within those seven notes, and you get exactly seven chords — your entire diatonic palette. Roman numerals name each by position and quality: UPPERCASE = major, lowercase = minor, ° = diminished.

NumeralChordNotesQualityRole
iAmA · C · Eminortonic — home
ii°BdimB · D · Fdiminishedunstable, passing only
IIICC · E · Gmajorrelative major (bright)
ivDmD · F · Aminorsubdominant
vEmE · G · Bminorweak dominant (see note)
VIFF · A · Cmajorsubmediant (warm)
VIIGG · B · Dmajorsubtonic (lifts)

Pattern for any natural-minor key: i · ii° · III · iv · v · VI · VII. Learn it once and it transposes (§4). Your workhorses (bold above): Am, C, Dm, F, G — and i, VI, III, VII, iv are the five you'll reach for constantly. Bdim is the rare one — diminished is unstable, used as a quick passing chord, never a landing spot.

The one note that isn't in your scale: G♯

In natural minor the v chord is Em (E·G·B) — and it's weak, it doesn't pull hard back to Am. So composers very often raise the G to G♯, turning Em into E major (E·G♯·B), a strong V that yanks you home. That G♯ is the single most common "borrowed" note in minor-key music — you'll meet it in the Andalusian cadence, the jazz turnaround, and doo-wop below. It is not in A natural minor; it's a deliberate import. Both versions work: the G♯ one is dramatic, the plain Em is softer. Every progression that uses it is flagged.

2The progression library — copy these

Each is one bar per chord unless noted; loop it. Roman numerals tell you the shape (portable to any minor key); the chord names and spelled notes are A minor specifically. The bass line under each is just the chord roots in order — that's §3, previewed.

Am Flo-fi / ambient
i – VI
Am (A·C·E) → F (F·A·C)
The one you already used. Warm, suspended, melancholy-but-soft. The two chords share A and C, so it glides. Endlessly loopable.
Bass: A → F
Am G F Gsynthwave / downtempo
i – VII – VI – VII
Am (A·C·E) → G (G·B·D) → F (F·A·C) → G (G·B·D)
The classic moody minor cruise — rocking between F and G under an Am home. All diatonic.
Bass: A → G → F → G
Am G F Esynthwave / cinematic
i – VII – VI – V  · the Andalusian cadence
Am (A·C·E) → G (G·B·D) → F (F·A·C) → E (E·G♯·B)
Dramatic, inevitable, that famous descending bass A–G–F–E. Flag: the last chord is normally E major (with G♯) for the pull; keep it Em (E·G·B) for a softer, diatonic version. Heard in "Hit the Road Jack," "Stray Cat Strut," "Sultans of Swing."
Bass: A → G → F → E  (a clean descending walk)
Bm7♭5 E7 Am7lo-fi / chillhop
iiø7 – V7 – i7  · the jazz turnaround
Bm7♭5 (B·D·F·A) → E7 (E·G♯·B·D) → Am7 (A·C·E·G)
The most important progression in jazz, inherited wholesale by lo-fi. Flag: strictly diatonic it'd be Bm7♭5 → Em7 → Am7; lo-fi almost always uses E7 (G♯) for the pull. "Studying at 2am."
Bass: B → E → A
Am7 Dm7 G7 Cmaj7lo-fi / chillhop
i7 – iv7 – VII7 – IIImaj7
Am7 (A·C·E·G) → Dm7 (D·F·A·C) → G7 (G·B·D·F) → Cmaj7 (C·E·G·B)
The most-cited lo-fi loop. Cycles through C-major's ii–V–I but starts on Am7 so it stays rooted in minor. All diatonic (G7's F is in the scale). Smooth, jazzy, nostalgic.
Bass: A → D → G → C
Am F Dm Emretro / sentimental
i – VI – iv – v  · minor doo-wop
Am (A·C·E) → F (F·A·C) → Dm (D·F·A) → Em (E·G·B)
The minor cousin of the 50s doo-wop sway. Use Em for pure diatonic, or E major (G♯) on the last chord for a stronger turnaround. Slow-dance nostalgia.
Bass: A → F → D → E
Am Dmambient / drone
i – iv  · two-chord vamp
Am (A·C·E) → Dm (D·F·A)  ·  hold each 2–4 bars
Minimal, hypnotic, no resolution pressure. Add 7ths (Am7 → Dm7) for more air. Perfect under a pad texture.
Bass: A … D … (room to move within each bar — see §3)
Am C F Gpop / lo-fi / uplifting
i – III – VI – VII  · the "4 chords" trick
Am (A·C·E) → C (C·E·G) → F (F·A·C) → G (G·B·D)
A minor and C major share all seven notes (C is the relative major). This is literally the famous pop "4 chords" loop read from Am — familiar and bright while staying in your key. Bittersweet, anthemic.
Bass: A → C → F → G
Am G F Cdowntempo / cinematic
i – VII – VI – III
Am (A·C·E) → G (G·B·D) → F (F·A·C) → C (C·E·G)
Smooth descending feel that lands on the bright relative major (C) instead of a tense V. All diatonic. Reflective, resolved.
Bass: A → G → F → C
Am C D Ffolk / cinematic
i – III – IV – VI  · "House of the Rising Sun" shape
Am (A·C·E) → C (C·E·G) → D (D·F♯·A) → F (F·A·C)
A brooding, narrative 6/8 lift. Flag: the D is D major (with F♯), another borrowed chord — that's what gives the song its distinctive rise. Keep Dm (D·F·A) for strictly diatonic. You play guitar — you'll recognize this one.
Bass: A → C → D → F

How to pick one

By mood and genre, not theory. Lo-fi/chillhop → the 7th-chord loops (Am7–Dm7–G7–Cmaj7, or the ii–V–i). Synthwave/cinematic → the descending ones (Andalusian Am–G–F–E, or Am–G–F–C). Ambient → the two-chord vamp (Am–Dm). Uplifting → the "4 chords" (Am–C–F–G). When unsure, start with i–VI (Am–F) — it's the one you already know works.

3The matching rule — bass that locks to chords and kick

This is the part you asked about directly: making the bass match the chords. The rule is short.

The default (start here every time)

One chord per bar, and the bass plays the ROOT of the current chord on the downbeat. When the chord changes, the bass moves to the new root. Under Am play A; under F play F; under G play G. The root is the chord's name-note — the first note in every spelling above. That's the whole foundation. It's why the Andalusian cadence sounds so strong: its bass walks A–G–F–E, a clean line that is the chord roots in sequence.

Here's a 2-chord loop (Am bar 1, F bar 2) with the bass rooting each chord and locked to your L1 kick (steps 1·5·9·13). Two bars shown side by side:

— bar 1: Am —                    — bar 2: F —
Step 1  5  9 13   |   1  5  9 13
Kick K  K  K  K   |   K  K  K  K
Bass A  A  A  A   |   F  F  F  F
Bass note = chord root, retriggered with the kick. When the chord changes (bar 2), the bass note changes to the new root. That's "matched."

Adding movement (once the root-on-downbeat default is solid)

What NOT to do

Rhythm: lock the bass to the kick — and the CT helps

Bass and kick should agree rhythmically. The reliable move (you met it in L1): the bass note hits with the kick, especially on each chord's downbeat — when kick and bass land on the same instant, the ear reads them as one powerful event instead of two muddy ones. In lo-fi/hip-hop the bass often plays sparse, syncopated notes sitting in the pockets around the kick; in synthwave it's a driving 8th- or 16th-note pulse on the root.

On the Circuit Tracks: your Synth 1 bass track is mono — one note at a time — which forces you to play roots and single passing notes. That's exactly the discipline this rule wants. (Established back in L1: Synth 1 = bass, Synth 2 = chords + melody.)

2-chord vs 4-chord loops

2-chord loop (e.g. Am–Dm, one bar each): the bass is just A … D … A … D. With few changes you have room to add movement within each bar — root on beat 1, then the 5th or octave later (A…E…, D…A…). This is where vamps get their groove.

4-chord loop (e.g. Am–G–F–E): the roots already make a melody (A–G–F–E), so the strongest move is just one root per bar, locked to the downbeat. Don't over-embellish — the chord changes are doing the work. Add a single walking note before a change only if it feels static.

4Where to steal more progressions

57th chords — the lo-fi color

A 7th chord = the triad plus one more stacked third on top (4 notes). That top note adds a gentle dissonance — "color" — without changing the chord's identity. Plain triads sound clean/pop; 7ths sound smoky, warm, slightly unresolved — the chillhop mood. Lo-fi is built on jazz harmony, so it leans on these hard.

NumeralChordNotesQuality
i7Am7A · C · E · Gminor 7th
ii7Bm7♭5B · D · F · Ahalf-diminished (ø7)
III7Cmaj7C · E · G · Bmajor 7th
iv7Dm7D · F · A · Cminor 7th
v7Em7E · G · B · Dminor 7th
VI7Fmaj7F · A · C · Emajor 7th
VII7G7G · B · D · Fdominant 7th

All diatonic (white keys only). To use them, take any triad progression in §2 and add the 7ths: Am→F becomes Am7→Fmaj7 (instant lo-fi). The flagship loop is Am7–Dm7–G7–Cmaj7 (#5). The bass rule doesn't change — still root on the downbeat (A, D, G, C). (Lo-fi harmony: Melodics, LANDR.)

6Today's build — a chord loop + its bassline

  1. Pick a progression by mood copy

    From §2, pick one that fits a genre you like. If unsure: Am–G–F–C (#9, all diatonic, no G♯ to worry about) or the lo-fi Am7–Dm7–G7–Cmaj7 (#5). Set Synth 2's scale to Natural Minor, root A (from L1).

  2. Play the chords on Synth 2 chords

    One chord per bar, held. Punch each triad's three notes (or four for 7ths) on the downbeat of its bar. Don't worry about voicing yet — block chords are fine. Loop it; let the changes establish the mood.

  3. Lay the root bass on Synth 1, locked to the kick bass

    On the mono bass track, play the root of each chord on the steps where your kick hits (1·5·9·13 from L1). Chord changes → bass note changes. This is the matching rule in one move.

  4. Add ONE movement, then stop extend

    Pick one: an octave jump on the root, a 5th later in a bar, or a single walking note into a change (§3). Hear it lock or clash. Then save the loop — chords + matched bass is today's win.

⏱ The 45-minute rule

A chord loop + a root bass locked to the kick is the whole win. If the timer rings after just block chords + roots — no movement, no 7ths — you still win: that's a matched chord/bass foundation, which is exactly what you said you couldn't build. Stop adding when it rings.

The Stop Rule (harmony edition)

Chord voicing (which octave each note sits in, inversions, extensions, 9ths/11ths) is a bottomless rabbit hole — you can re-voice one progression for an hour and it never feels "done." That's the loop trap in a tuxedo. Block chords, root bass on the kick, one movement. That's a matched harmony. Save and stop; voicing is a later lesson, not today's.

✓ What you just learned

You can read the seven chords A minor contains off the scale, you have a library of ten progressions to copy (with every note spelled and the borrowed G♯ flagged), and you own the matching rule: bass plays the chord's root on the downbeat, locked to the kick, and changes when the chord changes. "How do I make the chords match the bassline?" is now a one-sentence answer you can apply to any progression, in any key.

Accuracy notes (you verify theory — so here's the truth up front)

💬
I'm your teacher — ask me anything. The bass sounds muddy (kick and bass probably hit at different times — line them up)? A chord sounds wrong/sour (check you played the exact notes — one wrong note in a triad is audible)? The progression feels static (you're on a 4-chord loop with no movement, or a 2-chord loop that needs movement within the bar — §3)? Want to know if a progression you found elsewhere fits A minor (give me its chords and I'll convert it)? Tell me which progression and what you heard.

What's next

You now have all three sketch ingredients: varied drums (L4), groove (L3), and chords + matched bass (L5). The big remaining move is the mission's finish line:

My recommendation: arrangement next — you have drums, groove, and harmony; the one thing your last two attempts never reached is a finished track, and that's now the only missing piece. But your call. Run this, tell me which progression you built and how the bass locked in, and we pick from there.

Lesson 05 · Chords & the Bassline That Fits ← Lesson 4