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Prompt anatomy: the eight pillars
Almost every strong prompt is the same eight slots filled in — genre, instruments, mood, vocal, production, tempo, arc and harmony.
The eight slots
Treat a prompt as a form rather than a paragraph. You will not fill every slot every time, but knowing the slots exist stops you from accidentally leaving three of them blank and wondering why the output drifts.
| Pillar | What it answers | Example phrase |
|---|---|---|
| Genre | Which stylistic neighbourhood? | neo-soul, 90s boom bap |
| Instruments | What is actually playing? | Rhodes piano, upright bass, brushed kit |
| Mood & energy | How does it feel, how hard does it push? | wistful, restrained, slow burn |
| Vocal | Who is singing and how? | warm alto, breathy, close-mic |
| Production | What does the recording sound like? | tape saturation, narrow stereo, dry |
| Tempo & groove | How fast and what feel? | 78 BPM, laid-back swing |
| Song arc | How does it move over time? | sparse intro, full band from chorus 2 |
| Melody & harmony | What harmonic colour? | minor key, jazzy extended chords |
Order matters less than presence
Put genre first — it sets the frame everything else is read against — then instruments and vocal, then the texture terms. Beyond that, ordering has far less effect than simply having the slot filled at all. A prompt missing a vocal description will produce a different vocal every run; a prompt missing tempo will wander between drafts you meant to compare.
Filling slots you do not care about
- If you want no singing, the vocal slot becomes
instrumental— leaving it blank invites vocals. - If you do not care about the arc, skip it; an unfilled arc is far less costly than a wrong one.
- If a slot is genre-implied (boom bap already implies ~90 BPM), you can leave it out and reclaim the words.
- Never fill a slot with a superlative.
incredible productionis an empty slot wearing a hat.
Example
Practice
Write one prompt with all eight pillars filled, then produce three variants where you blank out a different pillar in each. Keep the notes side by side. The pillar whose removal changes the result most is the pillar that was doing the most work for that style — and the one you should protect first when you have to cut the prompt down to fit a length budget.