The prompt is fine. The structure is the problem.
You wrote dark brazilian funk, 130 bpm, heavy bass, aggressive. Four real instructions. Suno v5 gave you something that is technically all four and sounds like nothing in particular: a soft kick, a washed-out melody, a mix where the low end sits politely under everything else.
Nothing was rejected. That is the confusing part. The model read your prompt, found it under-specified, and did what any model does with an under-specified input — it returned the average of everything that description could mean. "Heavy bass" is a mood. It is not a decision about whether the sub is mono below 120Hz, whether it glides, or whether it is locked to the kick.
The fix is not a longer sentence. It is a different shape.
Why one line collapses and 17 fields don't
A single-line prompt hands the model one blob of text and asks it to infer the arrangement, the mix, the era and the performance all at once. Every ambiguity compounds: an unclear kick description bleeds into how the bass is placed, which changes the perceived tempo, which shifts the whole feel.
A structured prompt breaks that chain. When the kick, the bass, the melody and the percussion each own a field, an ambiguity in one no longer contaminates the others. You are not writing a description any more — you are filling in a session sheet, the same way a producer thinks about a mix: one decision per layer, and the layers are independent.
Three things change immediately:
Reproducibility. Two renders of the same structured prompt land in the same territory. Two renders of the same one-liner often don't, because the model resolved the ambiguity differently each time.
Debuggability. When the output is wrong, you know which field to edit. A one-liner gives you nothing to grab — you rewrite the whole thing and hope.
Commitment. A field named bpm expecting a number is much harder to fudge than a sentence that can say "fast-ish". Structure forces specificity by making vagueness look obviously wrong.
The 17 fields, and what each one is really for
The generator on this site emits this shape. It is worth understanding rather than just copying, because the reasoning transfers to any genre.
The identity block — style, length, bpm, key, era. Where the track lives. style carries genre, region and period as separate tokens rather than one fused label; era is the one people skip, and it is doing more work than they think, because a genre's production conventions changed enormously across decades.
The rhythm section — kick, bass, percussion, swing, drop. This is where most one-line prompts die. kick is not "heavy": it is a shape (does it glide?), a length (long tail or tight?), and a placement (which bar does it enter on?). bass states its relationship to the kick, because "locked to kick" and "moving independently" are two entirely different records. swing is the difference between a grid that sounds programmed and one that sounds played.
The melodic and vocal layer — melody, vocals. melody names an actual instrument and an interval, not "catchy synth". vocals specifies register, delivery, syllable density and how wet the vocal sits — the four things that decide whether a vocal sounds performed or pasted on.
The mix and shape — texture, atmosphere, production, dynamic, structure, mood. Mix language, not vibe language. "Mid-side EQ widened pads, mono center kick+bass" is an instruction an engineer could execute. "Epic and wide" is not.
The exits — negative. Every model has defaults it reaches for when unsure: an intro nobody asked for, a breakdown in the middle, a key change to manufacture a lift. The negative field closes those doors explicitly.
Copy-paste templates
Every template below is a real output of the VORAX generator, scored by the same engine the app uses — not an example written by hand.
Template 1 — quality score 100/100 (PREMIUM)
{"style":"brazilian funk-phonk omega, montagem rave phonk 2026, [110BPM F# minor + noise experimental funk + lo-fi vinyl texture + 2024 SP underground]",
"length":"2:30 minutes","bpm":110,"drop":"bar 4 beat 1","key":"F# minor",
"kick":"saturated distorted kick gritty crunch, full bar 1",
"bass":"808 sidechain-pumped to kick 4:1 ratio fast attack",
"melody":"dark tense synth stab D4-G#4 tritone terror",
"vocals":"ONE ultra-realistic female MC only, sultry breathy hook",
"percussion":"rimshot-only minimal pattern, ghost cabasa beneath",
"swing":"medium swing montagem bounce",
"structure":"no intro, full bar 1",
"texture":"mid-dominant cold digital mids tight sub",
"atmosphere":"matrix code static cold low mix",
"production":"minimal sparse single synth line clean, breathing space",
"era":"80s-analog classic synthesizer warmth",
"dynamic":"flat-wall consistent maximum energy",
"mood":"hypnotic cowbell funk dominant viral 2026",
"negative":"no intro, no break, no key change"}The flat-wall template: no build, no relief, 2:30 at one intensity. The token doing the heavy lifting is "808 sidechain-pumped to kick 4:1 ratio fast attack" — it states the relationship between two layers rather than describing each one, which is why the low end reads as one instrument instead of two fighting for the same space.
Template 2 — quality score 100/100 (PREMIUM)
{"style":"brazilian funk-phonk omega, montagem omega 2026, [111BPM D minor + queer trans baile funk + dual female MC + 2024 RJ queer]",
"length":"3 minutes","bpm":111,"drop":"bar 4 beat 1","key":"D minor",
"kick":"1980 1985 1989 cassette-era favela 808 sample crossover",
"bass":"808 slow long glide locked to kick, warm dark pressure",
"melody":"acid detuned pluck dark A4-C5 minor third",
"vocals":"deep male pitch -5st percussive chant 8 syl/sec dry",
"percussion":"agogo bells constant hats 16th dark snare",
"swing":"polyrhythmic swing 45% pocket cascade automotivo",
"structure":"no intro, full bar 1",
"texture":"mid-dominant warm analog mids tight sub",
"atmosphere":"matrix code static cold low mix",
"production":"2006 2010 2013 funk paulista evolution SP",
"era":"1980 1981 1985 1988 funk carioca origin era",
"dynamic":"evolving-layers progressive addition of elements",
"mood":"hypnotic drift phonk aggressive dominant viral 2026",
"negative":"no intro, no break, no key change"}The long-form template: three minutes that survive by adding, not by dropping. The decisive token is "polyrhythmic swing 45% pocket cascade automotivo" — a number on the swing is the difference between a grid that sounds quantised and one that sounds played, and at three minutes that difference is the whole record.
Template 3 — quality score 100/100 (PREMIUM)
{"style":"Brazilian funk mineiro Belo Horizonte dark 2024 2026, [112BPM F dorian + 1992 1993 1994 tamborzão Marechal Hermes Rio equipes + 1992-1994]",
"length":"0:45 minutes Reels short form","bpm":112,"drop":"bar 8 beat 1","key":"F dorian",
"kick":"melodic tonal kick tuned to key resonant body, full bar 1",
"bass":"synth bass portamento slow dark warm locked to kick",
"melody":"TR-909 hi-hat stab G4-D5 perfect fifth",
"vocals":"processed vocal sample texture low mix montagem",
"percussion":"industrial metallic clap reverb tail only",
"swing":"heavy swing funk carioca feel",
"structure":"no intro, full bar 1",
"texture":"mid-dominant glitch corrupted mids tight sub",
"atmosphere":"vinyl crackle lo-fi low mix",
"production":"hybrid balanced mid-density, selective layering",
"era":"2026-ultra-modern bleeding edge production",
"dynamic":"build-drop escalating tension into heavy impact",
"mood":"hypnotic mystical spiritual dominant viral",
"negative":"no intro, no break, no key change"}The short-form template: 45 seconds, drop held back to bar 8. The critical token is "melodic tonal kick tuned to key resonant body" — a kick tuned to the key stops being percussion and becomes the bass note, which is why the key field and the anchor have to agree. State two keys and you get a kick tuned to whichever one the model picked.
Pro tips you can actually hear
Say the bar the drop lands on. "drop":"bar 1 beat" and "drop":"bar 4 beat 1" produce audibly different records from otherwise identical prompts. "Big drop" produces neither — it produces an average.
Put a number on the vocal density. 8 syl/sec is a delivery instruction. "Fast rap" is a genre. The first one changes the performance; the second one changes almost nothing.
Name the instrument, not the adjective. "Moog Sub 37 bass stab" pulls the model toward a specific timbre. "Warm analog synth" pulls it toward the centre of everything warm and analog, which is to say nowhere.
Spend the negative field on defaults, not on taste. no intro, no break, no key change removes three things the model adds when uncertain. Listing genres you dislike does much less, because they were never going to appear.
Say each number exactly once. This is the failure mode nobody warns you about, and it hides in prompts that look well-built. If the style line carries a descriptor like [128BPM D major + ...] while the bpm field says 116 and the key field says F minor, the prompt states two tempos and two keys. Nothing errors. The model averages — and averaging tempo is exactly what a structured prompt exists to prevent. We found this in our own generator: on 8.000 sampled outputs, 91% contradicted themselves on tempo and 90% on key, worst case 120 BPM apart. Reconciling them is now enforced in the tool; in a prompt you write by hand, it is on you. Search your prompt for every number and make sure each one appears once.
Change one field at a time. The whole point of the structure is that fields are independent. Rewriting five at once and re-rendering tells you the output changed, not which decision changed it.
FAQ
Does Suno actually parse JSON?
Not as JSON, in the sense of a schema it validates. What the format does is force you to separate concerns and keep each instruction adjacent to its own label — and that separation is what survives into the output. The structure is a thinking tool that happens to also be machine-readable.
Do I need all 17 fields every time?
No. Fields you leave out get the model's default, which is sometimes exactly what you want. The ones that consistently earn their place are kick, bass, vocals, structure and negative — those are where under-specification does the most audible damage.
Why does the same prompt give different results?
Generation is stochastic and always will be. Structure narrows the spread: a structured prompt gives you variations on a decision, a one-liner gives you variations on an interpretation. Narrowing that spread is the entire game.
Conclusion
The gap between a prompt that works and one that doesn't is rarely vocabulary. It is whether the prompt made decisions or described a feeling. Seventeen fields is not bureaucracy — it is seventeen places where you were forced to commit to something the model would otherwise have averaged away.
Generate this structure free at /generator — every field filled from real genre vocabulary, 8 prompts a day, no signup. For unlimited generations and the full mode catalog, see Pro pricing.
