Bass Lines & Line Clichés
Turn the harmony upside down and read it from the bottom up. When the lowest note moves by step — diatonic or chromatic — it generates the chords above it, and that one idea explains line clichés, the minor lament, and passing diminished chords.
The bass as the organizing line
Most people build progressions chord-first: pick C, then F, then G, and let the bass land on whatever root comes next. Flip that around. Treat the bass line — the shape of the lowest voice — as the thing you design first, and the chords become a consequence of where that line goes.
This is more than a trick. A huge amount of familiar harmony is really a moving bass note reframing a held set of upper notes. Once you hear it that way, progressions that looked unrelated turn out to be the same line, harmonized differently — and you gain a reliable way to invent new ones: draw the bass, then dress it.
Stepwise diatonic motion
The simplest moving bass walks up or down the scale, one note at a time. A descending C-major bass — C – B – A – G — naturally harmonizes as C → G/B → Am → C/G (or G). Every bass note is a scale tone, so the chords stay in key; the smoothness comes entirely from the stepwise line.
Notice that two of those chords are inversions (G/B, C/G): putting a chord tone other than the root in the bass is exactly how you keep a stepwise line going without leaving the diatonic chords. This is why bass lines and slash chords are two views of the same thing.
Chromatic motion & line clichés
When the bass moves by half steps instead of scale steps, you get a line cliché: hold a chord on top, slide one voice (usually the bass) chromatically, and a chain of related chords spells itself out. The motion is so smooth and so recognizable that it has become a fixture of film scores, ballads, and jazz standards.
The core move: keep the upper notes of a chord still and let a single voice descend (or rise) by half steps. Each half step re-frames the held notes as a new chord — without re-fingering the shape on top.
The minor line cliché, step by step
The most famous line cliché is the minor "lament": a descending chromatic line under a held minor chord. Starting from A minor, the line walks A – G♯ – G – F♯ while the chord A–C–E stays on top. Watch how each bass step generates the next chord:
| Bass | Chord | What happens |
|---|---|---|
| A | Am | The home minor chord — root in the bass. |
| G♯ | Am(maj7) | The bass drops a half step; the held A–C–E now sits over G♯, spelling a maj7. |
| G | Am7 | Another half step down to G — the chord becomes a minor 7th. |
| F♯ | Am6 (or D7/F♯) | One more half step to F♯ — a minor 6th sound, the line resolving toward F. |
Four chords, but really one line. You never re-think the harmony — you move a single finger down the keyboard a half step at a time, and the chord names take care of themselves. This exact figure has carried countless minor-key songs and themes.
The major line cliché
The same idea works in major, usually with the chromatic line moving upwardthrough an inner voice. Over a held C major chord, raising the fifth step by step — G – G♯ – A — produces C → C+ → C6 (or an Am sound), an unmistakable bright, lifting cliché.
A descending major version walks the bass C – B – B♭ – A, harmonized as C → Cmaj7/B → C7/B♭ → F/A — the bass stepping down chromatically while the chord on top barely changes. Whether the line ascends or descends, the principle is identical: one chromatic voice does the work of a whole chain of chords.
Passing diminished chords
When a stepwise bass needs to cross the gap between two diatonic chords whose roots are a whole step apart, a passing diminished chord fills it. Between C and Dm — roots a whole step apart — insert C♯°7 so the bass walks C → C♯ → D by half steps.
The diminished chord has no harmonic destination of its own here; it is purely a connector, a chromatic stepping-stone that keeps the bass line moving smoothly. Diminished 7ths are perfect for this because they sit symmetrically between chords and resolve easily in any direction — the ideal glue for a walking, half-step bass.
Frequently asked questions
What is a line cliché?
A line cliché is a progression generated by one voice — usually the bass or an inner voice — moving by step, most often chromatically, while the other notes of a chord stay put. Holding a chord and sliding a single voice down by half steps spells out a chain of related chords. The minor "lament" (i, i(maj7), i7, i6) is the best-known example.
How does a bass line create harmony?
When you hold a set of upper notes and change only the bass beneath them, each new bass note re-frames the same notes as a different chord. C–E–G over C is C major; over A it becomes A minor 7th; over F it becomes Fmaj7. The moving bass note generates a new harmony on every step without you re-fingering the chord on top.
What is the difference between a walking bass and a line cliché?
A walking bass is a steady, mostly stepwise bass line (common in jazz and blues) that outlines the chords beat by beat, usually moving in quarter notes. A line cliché is a specific, slower-moving figure where the bass (or an inner voice) descends or ascends by half steps to generate a recognizable chord chain. A walking bass improvises motion through given chords; a line cliché defines the chords itself.
What is a passing diminished chord?
A passing diminished chord is a diminished 7th inserted between two diatonic chords to connect their roots by step in the bass. Between I and ii in C — C and Dm — a ♯I° (C♯ diminished) lets the bass walk C → C♯ → D smoothly. The diminished chord has no function of its own here; it exists to fill the gap and keep the bass moving by half step.
Why do so many songs use a descending bass line?
A bass that steps downward creates a feeling of inevitability and gentle gravity — each note pulls toward the next. Because every step can be harmonized several ways, a single descending bass shape can carry very different progressions, which is why it underpins everything from baroque laments to pop ballads and the classic "Stairway"-style intro.
Do I read a bass line from the chord symbols or write it first?
Both directions work. Often the chords come first and you choose a bass note for each (frequently the root, sometimes an inversion for smoother motion). But composing the bass line first — deciding it will descend by step from the tonic — and then harmonizing each note is exactly how line clichés are built. Thinking bass-first is a powerful way to generate fresh progressions.