Beta opening soon

Stop Thinking.
Start Reacting.

The reflex trainer that turns Nashville Numbers into muscle memory — in any key, under pressure.

KEY OF G
96% accuracy
720ms avg
tap the chord
♭7
✓ F — 680ms
C#
D#
F#
G#
A#
C
D
E
F
G
A
B

You know the theory.
But can you react fast enough?

Most musicians "understand" Nashville Numbers — until the key changes on stage and their brain freezes.

Key Change Freeze

The band leader says "up two keys" and your hands stop. You know the theory, but your fingers can't keep up in real time.

🎯

Theory ≠ Performance

Knowing I–V–vi–IV on paper is not the same as instantly playing it in E♭. There's a gap between knowledge and reflex.

📊

No Way to Measure

YouTube teaches theory. Books explain harmony. But nothing lets you quantify your tonal reflex and track real improvement over time.

Not another theory app.
A reflex trainer.

Chord Reflex doesn't teach you more theory — it trains you to react so fast that thinking becomes optional.

780ms

Speed

Track your reaction time in milliseconds. Lightning-fast responses earn bonus points and unlock achievements.

96%

Accuracy

Per-key accuracy tracking shows exactly where you're solid and where you need work. No hiding behind easy keys.

Reflex

EWMA trend analysis shows your long-term trajectory. One bad session won't erase weeks of progress.

Three steps. Five minutes a day.

Short, focused sessions that build real muscle memory over time.

Choose Your Key

Pick a single key to focus on, or turn on Random Keys mode to train across all 12 keys — just like a real session.

React to the Degree

A scale degree flashes on screen. Tap the correct chord on the keyboard — as fast as you can. Your reaction time is recorded in milliseconds.

Track Your Progress

See accuracy and speed trends for every key. Unlock speed stats when your accuracy proves you're ready. Watch yourself improve over weeks.

Your improvement,
measured in milliseconds.

Chord Reflex tracks every answer — speed, accuracy, and trend — so you always know exactly where you stand.

No more guessing if you're "getting better." See your reflex sharpen in real data.

The EWMA algorithm ensures one bad day doesn't tank your stats. Only consistent change moves the needle.

780ms
Average Reaction Time
↑ 120ms faster than last week
🎯
96.2%
Overall Accuracy
↑ Improving steadily
🔥
23
Best Streak
3.0x multiplier unlocked
📈
12 / 12
Keys Practiced
Session-Ready across all keys

Built by a musician, for musicians.

Every feature exists because a real musician needed it during real practice.

Single Key & Random Keys Mode

Focus on one key or train across all 12 with automatic key changes every 10 questions.

Millisecond Reaction Tracking

Every answer timed to the millisecond. Speed bonuses reward lightning-fast reflexes.

Per-Key Performance Stats

See accuracy and speed for each of the 12 keys. Know exactly where your weak spots are.

EWMA Trend Analysis

Exponentially weighted moving averages show your true trajectory, not just today's score.

Score & Streak System

Earn points, build streaks up to 3x multiplier, and compete against your own best.

Audio & Haptic Feedback

Instant sound and haptic response for correct and incorrect answers. Feels like a real instrument.

Born from a real pain point.

I kept freezing every time the key changed during worship rehearsal. I knew the Nashville Numbers — on paper. But under pressure, my fingers couldn't keep up. I looked for a tool that could train my reflex, not teach me more theory. It didn't exist. So I built it myself. Every feature in Chord Reflex exists because I genuinely needed it.

The Builder
iOS Developer & Musician

Ready to train your reflex?

Join the beta and be the first to turn your Nashville Number knowledge into real muscle memory.

Common Questions

It's a method of representing chords by their scale degree (1, 2, 3…) instead of note names (C, D, E…). This makes it easy to transpose songs to any key instantly — if you have the reflex for it.

You should know basic chords and scale degrees. Chord Reflex is not a theory teacher — it's a reflex trainer for musicians who already understand the basics but want to react faster.

iOS first (iPhone). iPad and Mac support are planned for future versions.

Yes. Beta testers get free access via TestFlight. Your feedback will directly shape the final product. A Pro version with additional features will be available at launch.

MIDI input is planned for v2, so you can practice with your actual keyboard. The current version uses an on-screen piano keyboard.