Music Theory Basics for Songwriters: Scales, Chord Progressions, Harmony

Whether you write pop hooks, indie ballads, or cinematic cues, a grasp of scales, chord progressions, and harmony helps you write more intentionally, troubleshoot stuck sections, and communicate with collaborators. This tutorial focuses on practical tools you can use immediately while composing, without getting lost in abstract terminology.

The big picture: keys, intervals, and the sound of home

• A key gives your song a “home base” (tonic). In C major, C is home; in A minor, A is home.
• Intervals are the distances between notes measured in semitones (half steps). Two key intervals for songwriters:
  • Major/minor third: defines chord quality (C–E is a major third; A–C is a minor third).
  • Perfect fifth: stabilizing (C–G). Root motion by fifths makes progressions feel strong.
• Most melodies and chords draw from a scale—a set of notes chosen for a specific sound. Choosing a scale is like choosing a color palette.

Scales songwriters actually use

Major and minor (your default palettes)

• Major scale formula (whole = W, half = H): W-W-H-W-W-W-H. Example: C major = C D E F G A B.
• Natural minor: W-H-W-W-H-W-W. Example: A natural minor = A B C D E F G.
• Harmonic minor: raise the 7th in natural minor (G# in A minor). This creates a strong V chord (E major) that pulls back to i (A minor).
• Melodic minor (ascending): raise 6th and 7th ascending (F# G# in A), revert to natural minor descending. Useful for jazz-leaning colors, but for pop/rock, you can cherry-pick the raised 6 or 7 as needed.

Practical tip: If your chorus feels flat in minor, try harmonic minor for the chorus only to unlock a major V (E in A minor) and greater lift.

Pentatonic and modal flavors

• Major pentatonic: 1 2 3 5 6 (C D E G A). Great for singable melodies that avoid tension notes 4 and 7.
• Minor pentatonic: 1 b3 4 5 b7 (A C D E G). Foundation of countless rock, blues, and pop hooks.
• Mode flavors:
  • Dorian (minor with raised 6): A Dorian = A B C D E F# G. Keeps minor vibe but brighter. Works for verses that need motion without full-on major.
  • Mixolydian (major with b7): G Mixolydian = G A B C D E F. Great for rock progressions like I-bVII-IV (G-F-C).

Songwriting move: Choose one “home” scale and allow occasional borrowed tones for color (see Section “Borrowed chords and modal mixture”).

From scales to chords: building your harmonic toolbox

Build triads by stacking every other note of the scale.

Diatonic triads in major (example: C major)

• I C major (C E G)
• ii D minor (D F A)
• iii E minor (E G B)
• IV F major (F A C)
• V G major (G B D)
• vi A minor (A C E)
• vii° B diminished (B D F)

With sevenths:

• Imaj7, ii7, iii7, IVmaj7, V7, vi7, viiø7 (half-diminished)

Diatonic triads in natural minor (example: A minor)

• i A minor, ii° B diminished, III C major, iv D minor, v E minor, VI F major, VII G major Using harmonic minor gives V (E major) and vii° (G# diminished), adding pull back to i.

Practical uses:

• V7 wants to resolve to I (or i). Leverage this tension/release at phrase ends.
• ii is the dominant’s helper. ii–V–I is a universal cadence; in pop you’ll often hear ii–V flowing into I or vi.

Functional harmony: tonic, predominant, dominant

Think in three functions rather than chord names:

• Tonic (rest/home): I and vi (and sometimes iii). Use to start, land, or breathe.
• Predominant (set up tension): ii and IV. Prepares the dominant.
• Dominant (tension): V and vii°. Wants to resolve to tonic.

Common cadences:

• Authentic: V → I (strong resolution). With 7th in V and 3rd in the melody, even stronger (V7–I with leading tone B→C in C major).
• Plagal: IV → I (“Amen” cadence). Softer resolution, great for codas or gospel vibes.
• Deceptive: V → vi (in major). Builds expectation then sidesteps to a related tonic substitute. Good for surprising a chorus landing.
• Half cadence: ends on V. Good for ending a verse that leads into a chorus.

Guideline: Move through functions in order—Tonic → Predominant → Dominant → Tonic—to shape phrases and sections.

Progressions that just work

Try these in C major (transpose to your key as needed):

• I–V–vi–IV (C–G–Am–F): Modern pop backbone. Strong bass motion and clear melodic space.
• vi–IV–I–V (Am–F–C–G): Emotional verse loop; ends with V which begs for continuation.
• I–vi–IV–V (C–Am–F–G): Classic doo-wop. Great for bridges or throwback vibes.
• ii–V–I (Dm–G–C): Use as a turnaround at phrase ends or to reset to the tonic.
• IV–I–V (F–C–G): Country/folk-friendly; try adding a vi: IV–I–vi–V.
• 12-bar blues in A: A7 | D7 | A7 | A7 | D7 | D7 | A7 | A7 | E7 | D7 | A7 | E7. Dominant sevenths throughout for grit.

Minor-key options in A minor:

• i–iv–V (Am–Dm–E): Harmonic minor creates that major V for pull.
• i–bVII–bVI–bVII (Am–G–F–G): Aeolian rock. Works well with minor pentatonic melodies.
• i–VI–III–VII (Am–F–C–G): Broad, cinematic lift in choruses.

Tips for voice-leading:

• Keep common tones between chords (C common to C and Am; F between Dm7 and F).
• Favor stepwise motion in top line and bass where possible.
• Use 7ths on V and 6ths on IV to smooth voice-leading (e.g., F6 → G7 → C).

Secondary dominants: add tension without changing key

Secondary dominants temporarily tonicize a diatonic chord.

• V/V in C major is D7 (dominant of G). Progression: C → D7 → G → C. Hear the extra pull into G before returning home.
• V/ii is A7 resolving to Dm: C → A7 → Dm → G → C.
• Use sparingly in pop; feature them at pre-chorus peaks or turnarounds.

Quick recipe:

1. Pick the target diatonic chord (ii, iii, IV, V, or vi).
2. Build a major V7 on its root (target = G → D7; target = Dm → A7).
3. Resolve to target, then continue functionally (target → V → I).

Borrowed chords and modal mixture

Borrow from the parallel minor (in C major, borrow from C minor) for color:

• bVII (Bb) and bVI (Ab): Rock staples. Try C–Bb–F (I–bVII–IV, Mixolydian flavor).
• iv (Fm) in major: melancholic twist before V or I. Example: C–Fm–G–C.
• ii° (D°) as a passing predominant: C–D°–Em–F–G–C.
• bIII (Eb) for a surprise lift into IV or V: C–Eb–F–G.

Best practice: Use borrowed chords at section starts or pivot lines to signal a new emotional hue. Keep melody anchored to shared tones to avoid clashes.

Melodic writing that fits your harmony

• Target chord tones (1, 3, 5, and 7) on strong beats. Non-chord tones (passing, neighbor, suspension) belong on weaker beats and resolve by step.
• Characteristic pulls:
  • 4 resolves to 3 in major (F→E over C).
  • 7 resolves to 1 (B→C in C).
  • 6 resolves to 5 in minor (F→E in A minor) unless you’re leaning Dorian.
• Shape: Use arch contours (rise then fall) for natural phrasing; aim the melodic high point near the chorus or bar 7 of an 8-bar phrase.
• Pentatonic for safety, diatonic for breadth, chromatic approach for spice (approach a target note by half-step above or below).

Exercise: Write a melody over I–V–vi–IV using only major pentatonic. Then reharmonize the same melody with ii–V–I–vi and adjust only non-chord tones to keep targets intact.

Bass, inversions, and harmonic rhythm

• Bass drives feel. Outline roots clearly at phrase starts, then use stepwise motion and chord inversions to connect.
• Inversions (slash chords) smooth bass:
  • C–G/B–Am–F creates C–B–A–F bass steps instead of leaps.
  • In minor, Am–E/G#–Am keeps tension with a leading bass tone.
• Passing chords:
  • Between C and Dm, slip in C#° (leading-tone diminished) to staircase the bass: C–C#°–Dm.
• Harmonic rhythm:
  • Faster changes (two chords per bar) add energy (great for pre-choruses).
  • Slower changes (one chord per two bars) create space (verses, intros).
• Leave room for melody: If your melody is rhythmically busy, lengthen chord durations; if the melody sustains, consider adding a passing chord or bass movement to maintain interest.

Extensions and color tones (easy wins)

• Add 7ths: Imaj7 for lushness (Cmaj7), ii7 for smoothness (Dm7), V7 for tension (G7).
• 9ths: Cmaj9 (add D) or Dm9 (add E) for modern warmth. Keep the 9th away from the melody if it clashes.
• Sus chords: Vsus4 (Gsus4) resolving to V hooks the listener; try it before cadence points.
• Add6: IV6 (F6) moving to V7 (G7) softens the buildup.

Rule of thumb: One extension per chord is often enough in pop contexts; save stacks (9, 11, 13) for spacious arrangements.

Putting it together: a songwriter’s workflow

1. Pick a key around your vocal range. If your chorus tops out uncomfortably, transpose or switch to Mixolydian to lower the leading tone tension.
2. Choose a primary palette:
   • Major with occasional mixture (bVII, iv) for modern pop/rock.
   • Minor with a major V (harmonic minor) for strong choruses.
   • Modal (Dorian/Mixolydian) for vibe-forward tracks.
3. Sketch a progression by function:
   • Verse: I (tonic) → IV or ii (predominant) → V (dominant) → I or vi (tonic-ish).
   • Pre-chorus: escalate with ii–V chains or a secondary dominant (V/V).
   • Chorus: land on I (major) or i (minor); consider using borrowed bVI or IV for lift.
4. Craft bass and inversions to connect roots smoothly.
5. Write melody targeting thirds and sevenths of the underlying chords at phrase peaks.
6. Add color: try V7, Imaj7, or a borrowed iv. If the section turns dark, use bVI; for brightness, use 9ths on tonic and predominant.
7. Refine harmonic rhythm: increase chord pace into the chorus; give the chorus more “home” by holding I longer.
8. Test in another key to ensure the song survives transposition (melodic and harmonic strength, not just instrument-friendly shapes).

Common pitfalls and how to avoid them

• Chord soup: Too many borrowed/secondary chords can blur the key. Limit “spice” to 1–2 moves per 8 bars unless the style demands it.
• Static sections: If a verse loops one chord, vary bass notes (C–C/E–C/G) or add a passing diminished to build momentum.
• Melody-chord clashes: If the melody sits on the 4 over I (F over C), either treat it as a suspension resolving to E or shift harmony to IV briefly.
• Overusing parallel motion: If all parts move together in the same direction, the harmony feels blocky. Introduce contrary motion in bass or inner voices.
• Ignoring cadences: End phrases clearly. Even a quick V→I at the line end makes lyrics feel punctuated.
• Modulation without setup: Use a secondary dominant or pivot chord shared by both keys to avoid jarring jumps.

Practice plans (10–15 minutes each)

• Transpose lab: Take I–V–vi–IV through five keys. In each, write a 1-bar melody hitting 3rds of each chord.
• Borrowed color drill: In C major, write two 4-bar phrases—one using bVII (Bb) and one using iv (Fm). Compare moods.
• Secondary dominant mini: Write C → D7 → G → C and improvise melody emphasizing the 3rd of each chord (E, F#, B, E).
• Bass connector: Turn C–Am–F–G into C–G/B–Am–F–G with stepwise bass. Note how the groove tightens.
• Minor lift: In A minor, rewrite a chorus using E major (V) and test if the vocal lifts without transposing.

Quick reference progressions to spark sections

• Verse starters:
  • I–vi–IV–V
  • vi–IV–I–V
  • i–VII–VI–VII (minor)
• Pre-chorus builders:
  • IV–ii–V
  • ii–V/V–V
  • iv–bVI–V (major with mixture)
• Chorus landings:
  • I–V–vi–IV
  • I–IV–V–I
  • i–VI–III–VII (minor)
• Bridge contrasts:
  • ii–V–iii–vi (circle of fifths chunk)
  • bVI–bVII–I (borrowed lift)
  • IV–iv–I (classic mixture turn)

Final takeaway: Think in functions, choose a clear palette, and use tension/release purposefully. With a handful of scales, a functional roadmap, and a few color moves, you can craft progressions that support memorable melodies and emotionally coherent songs.