How the Songbrain Virality Score Actually Works
May 18, 2026 · Updated October 2026 · 7 min read
Three parts, one number
Example output: 0.45 × 76 + 0.35 × 80 + 0.20 × 78 = 77.8, shown as 78. Instrumentals use 40% virality potential and 60% quality.
Key takeaways
- →The Virality Score comes from a fixed pipeline — audio analysis, a cloud audio model and lyric transcription — and takes about a minute for a 3-minute track.
- →The formula is fixed and simple: 45% virality potential, 35% quality, 20% lyrics (40/60 for instrumentals). The same file always gets the same score.
- →Every part is rated in the context of the genre: a 90 in metalcore and a 90 in K-pop mean equally well-positioned inside each genre's own language.
- →It's an iteration tool, not a verdict — upload v1, adjust hook placement and structure, re-upload v2 and watch the score move.
Most "AI music analysis" tools give you a number and a vibe. You don't know what went into it, you don't know what would change it, and you definitely don't know whether it's telling you about your song or about itself.
We'd rather just show you the pipeline. The Virality Score is built in eight stages, and the final number is a fixed formula in plain code. Here's what each stage does and how the parts combine.
The pipeline, end to end
When you upload a song, it goes through this sequence — sequentially, because every stage builds on the previous one's output. Total time: about a minute for a 3-minute track.
Tempo, key, beat grid, loudness (LUFS), dynamic range, energy over time — the same vocabulary mastering engineers use. Plain signal analysis, no guessing.
A cloud audio model listens to the full track and places it in 1 of 37 genres, names the instruments and describes the sound — the granularity that actually maps to discovery (phonk ≠ trap, shoegaze ≠ indie-rock).
Full lyric transcript with word-level timestamps, so every line can be tied to the second it is sung.
The lyrics are judged as they are heard: wordplay and imagery, emotional resonance, memorability of the hook lines, flow and delivery. Instrumentals skip this part.
The 3–15 second windows with the strongest hook signal, found from energy peaks, vocal density and where the lyric payoff lands.
How catchy the hook is, how fast the track earns attention from second one, and how shareable it is as a short clip — rated against the conventions of its genre.
Production, mix and vocal performance. Rated in the context of the genre, so a lo-fi bedroom track isn't graded against a stadium pop master.
Final 0–100 number, computed in plain code from the parts above: 45% virality potential, 35% quality, 20% lyrics. Instrumentals: 40% virality potential, 60% quality. The same file always gets the same score.
What gets weighted heavily — and what doesn't
The parts don't count equally. How well the song works as a short clip matters most; quality and lyrics decide the rest. The weighting is fixed — no hidden adjustments:
| Dimension | Weight | Why |
|---|---|---|
| Virality potential | 45% | Hook catchiness, attention from second one, share potential as a short clip. |
| Quality | 35% | Production, mix and vocal performance in the context of the genre. |
| Lyrics | 20% | Wordplay, emotional resonance, memorable lines, flow and delivery. |
| Instrumentals | 40 / 60 | No lyrics to rate: 40% virality potential, 60% quality. |
Why the score is genre-relative
A 90 in pop and a 90 in shoegaze do not mean the same thing in absolute production terms — they mean both tracks are equally well positioned to go viral inside their own genre's viral language. A shoegaze track that sounds like pop would be a failure as shoegaze; a pop track with shoegaze production would confuse the algorithm.
So every part of the score is rated in the context of the genre the track was placed in. If the genre is misclassified (rare, but it happens with hybrid tracks), the score is off too — and you'll see this on your report because the genre label will look wrong.
Why structure matters more than people expect
Virality is structural. Where the hook lands, how often it recurs, and how fast the track earns attention from second one decide whether a clip survives the scroll.
That's why the biggest part of the score, virality potential, looks at exactly that — hook catchiness and how fast the track earns attention. Your Best Moments come from the same structural evidence, and the score breakdown on your report shows which part carried (or capped) the final number.
What the score does not do
- It does not predict revenue. Viral ≠ monetizable.
- It does not account for promotion, posting cadence, audience size, label support. Pure song-level signal.
- It does not punish "non-trendy" songs — if your genre favors longer hooks or slower builds, the song is rated against that.
- It is not a creative judgment. A 60 doesn't mean the song is bad. It means in the current viral language of its genre, it would have to fight harder for placement.
What you can do with it
The score is most useful when you compare it across versions of the same track. Upload v1, see what falls short. Adjust the hook placement, tighten the mix, restructure the intro. Re-upload as v2. Watch the score move. That's the feedback loop the product is built for — it's an iteration tool, not a verdict.
See your score in about a minute.
First song free, 25 more credits on signup — no credit card.