Song Structure
Theory tells you which chords sound good together; structure tells you how to arrange them into a song. Here are the forms most music is built on, and what each section is for.
The sections — what each part does
| Section | Its job |
|---|
| Intro | Set the mood and ease the listener in. |
| Verse | Tells the story — melody stays similar, the lyrics change each time. |
| Pre-Chorus | Builds tension and lifts you into the chorus. |
| Chorus | The hook — the biggest, catchiest, most-repeated part. |
| Bridge | Contrast: new chords or melody, usually once, before the final chorus. |
| Outro | Wind down, resolve, or fade out. |
Common forms
Modern Pop / Hip-Hop
Intro · Verse · Chorus · Verse · Chorus · Bridge · Chorus · Outro
AABA (32-bar)
Two A sections, a contrasting B (the bridge), then A again. The backbone of jazz standards and older pop.
Verse–Chorus
The workhorse of pop and rock — alternate the two, drop a bridge in late for contrast.
12-Bar Blues / Strophic
A repeating fixed form (see the Blues tab), or the same music every verse (folk, ballads).
BEAT TIP: Think in 4- and 8-bar blocks. Most sections are 8 or 16 bars; the chorus often reuses the verse chords but with a fuller arrangement — more layers, not more theory.
Melody Guide — Playing Over Chord Progressions
This guide explains which notes, scales, and techniques work best for playing melodies over common chord progressions on piano. Knowing what chords are playing tells you which notes are safe, which create tension, and which to avoid.
THE CORE PRINCIPLE:
Every chord is built from scale tones. The notes of the chord itself are always safe. The other notes of the key scale are passing tones — use them briefly to move between chord tones. Notes outside the scale are tension tones — use them deliberately for colour, then resolve.
Call & Response — Phrases That Talk to Each Other
Music is built from phrases — short musical sentences. Pair two of them as a question and an answer and the listener's ear follows the conversation. Classical theory calls them the antecedent and consequent; gospel, blues and hip-hop call it call & response.
Harmony asks and answers
A phrase that ends on the V chord sounds unfinished — a half cadence. One that goes V → I sounds finished — an authentic cadence. That's the whole engine of a question and an answer (more in Cadences).
▶ Question: I–vi–IV–V▶ Answer: I–vi–V–I
Melody asks and answers
The call ends on an unstable scale degree (the 2nd, 5th or 7th); the answer keeps the same rhythm and lands on a stable one (the root or 3rd). Usually only the last couple of notes change.
▶ Call → answer
Phrase lengths
Questions and answers come in matching sizes: 2 + 2 bars for a hook, 4 + 4 bars for a verse (an 8-bar period). Matching lengths are what make the answer feel like a reply.
The blues form: A A B
The 12-bar blues is call & response at the scale of a whole verse: a line (A), the line again (A), then the line that answers both (B).
Bass Lines — Connecting the Chords to the Drums
The bass plays the lowest note of the harmony and locks to the kick. Get it right and a progression feels solid and deliberate; get it wrong and the whole track feels unsure of itself. All examples below play over C – Am – F – G.
1 · Roots on the one
Play the root of each chord as it arrives. Simple, powerful, and the foundation of most hip-hop and trap 808s.
▶ Roots
2 · Root & fifth
Alternate the root with its 5th. The 5th is always safe — it's in the chord — and it adds bounce without changing the harmony.
▶ Root–fifth
3 · Octave jumps
Bounce between the root and the same note an octave up. Instant movement — the disco and house classic.
▶ Octaves
4 · Approach notes
Step into the next root from a note above or below it. Here B walks into A, G into F, F# into G and B back home to C — the bass leads the ear to each chord change.
▶ Walking
The 808 rules
- One low-end owner at a time. If the 808 and another bass share the sub, one has to go — see Common Clashes.
- Lock to the kick. Start bass notes with the kick, or deliberately between kicks — never randomly near them.
- Tune it to the key. An 808 is a pitched note. Find its root (Ableton's Tuner works) and play the song's chord roots.
- Glide on purpose. Slides between notes (Glide in Simpler / Operator) sound best between roots of the progression, not random notes.
- Keep it mono. Low end belongs in the centre — try it in the Stereo Field.
LISTEN FOR IT: Mute everything except the drums and bass. If those two alone make you nod your head, the song has a foundation.
