Ear training for jazz musicians who've outgrown their app.
Scale-degree-first training built for the long road to hearing altered dominants, modal interchange, and quartal voicings — with analytics that show which specific sounds trip you up. Advanced jazz modules ship monthly.
Free to try, no signup · Cancel anytime · 14-day refund · No ads, ever
The weakness you already half-knew, measured.
You already generate this data every session. We just make it the product.
How it works
Inside real harmonic context.
7th chords by function, scale degrees in key, cadences and ii-V-I — the foundation everything jazz-specific is built on.
Every attempt feeds the matrix.
Which 7th qualities you mix up, which keys break you, which intervals slip when descending.
Drill the gaps, not the familiar.
Auto-generated sessions target the sounds you're weakest on — the ones you'd skip in self-practice.
For players who already know
All 7th-chord qualities, in key
maj7, m7, dom7, m7♭5, dim7, mM7. Drilled diatonically and in mixed sets across every key.
Cadences, ii-V-I, secondary dominants
Hear chord function, not just chord names. Authentic vs deceptive, V/V vs V/vi, modulation vs stay-in-key.
Matrix-level granularity
Per-quality, per-direction, per-key. Not just "78%".
Sing-back for solfege
Browser-native mic, cents-accurate. Because jazz school never stops.
How Fifths compares
We're not trying to replace method books or lessons. We're the measurement layer your practice doesn't have.
| EarMaster | Sonofield | Fifths | |
|---|---|---|---|
| Price | $3–6/mo | $18.95/mo | $4.99/mo |
| All 7th-chord qualities | partial | ✓ | ✓ |
| Cadence + ii-V-I drills | limited | partial | ✓ |
| Secondary dominants | — | — | ✓ |
| Altered dominants | — | partial | on roadmap (monthly drops) |
| Modal interchange / voicings | — | — | on roadmap (monthly drops) |
| Works on web | desktop app | iOS only | ✓ anywhere |
| Matrix analytics | ✗ | ✗ | ✓ |
| Total modules at launch | 2,500+ | ~200 | ~50 (jazz content monthly) |
Frequently asked
I already finished Sonofield. Why switch?
Sonofield's great for the method. We add measurement — after every session you see which qualities or scale-degrees still fool you, not just "78%." And we're roughly a quarter the price.
What's in the advanced-modules pipeline?
Today: cadences, pop progressions, ii-V-I in major and minor, secondary dominants, modulation detection. Coming next (1–2 new Pro modules per month, prioritized from paying-user signals): altered dominants (♭9, ♯9, ♯11, ♭13), modal interchange, voicings (closed / drop-2 / quartal / upper-structure), and post-tonal interval-class work for the deepest tier.
Is there a free tier?
Yes. Full baseline curriculum + 7-day analytics. Pro unlocks advanced chord modules + unlimited history + mic input + auto-drill.
Do I need a MIDI keyboard?
No. Web + headphones + piano samples built in. Add a keyboard later if you want input on specific drills.
Is it live now?
Yes — practice today at app.fifths.io. The $99 lifetime is reserved for the first 100 seats; once they're claimed, the tier closes forever.
Pricing — fair and clear
Free forever. Pro unlocks unlimited history, weak-item drill sessions, and mic-input scoring.
- Full curriculum
- Last 7 days of stats
- No signup needed
- Unlimited history
- Weak-item drill sessions
- Mic-input pitch scoring
- Everything in Pro Monthly
- ~$3.33/mo equivalent
- Cancel anytime
- All Pro features, forever
- Future curriculum included
- Closes after 100 sales
Cancel anytime · 14-day full refund · No ads, ever
Chops need measurement.
Practice for free at app.fifths.io — no signup needed for the first lessons.
Want the lifetime tier instead?