Your 2 AM Practice Partner.
Async drill companion for Open Studio students.
Open Studio has the live sessions. Adam and Peter have the concepts. Chord Trainer is what happens at 2 AM when no live class is running — MIDI-validated, timed speed drills that turn voicing knowledge into muscle memory.
The Opportunity
Open Studio already has the best jazz piano instruction online — 56K+ players, 2500+ lessons, live sessions every week, Guided Practice, Harmony Games. You've built an incredible ecosystem.
One piece that's still missing: async, MIDI-validated drill practice for the hours between live sessions. Students understand shell voicings after the class — they just can't play them in all 12 keys yet. That transformation happens through repetition, not re-watching. Chord Trainer is that repetition tool.
How It Works Alongside Open Studio
Students use it between sessions — or open the demo right after a lesson to drill the same voicings.
1. Watch the Lesson
Student watches Adam teach shell voicings, rootless concepts, or any chord topic.
2. Click "Practice"
A new tab opens with the trainer pre-loaded for exactly those voicings. One click to start drilling.
3. Track Progress
MIDI validates every chord. Weakness analysis shows which keys need work. Speed improves session by session.
Inside Your Platform
A new "Practice" tab — right next to Overview, Materials, and Shortcuts. Preview — embed integration ready for pilot
What Students Can Practice
Every concept Adam & Peter teach has a matching drill.
Shell Voicings (3-7)
"The bread and butter" — drill through all 12 keys
Rootless A (Bill Evans)
3-5-7-9 voicings, the classic left-hand sound
Rootless B
7-9-3-5, the complement to A voicings
ii-V-I Progressions
The most common jazz cadence, all 12 keys
I-vi-ii-V Turnarounds
Full rhythm changes turnaround
Custom Progressions
Autumn Leaves, All The Things, any standard
Inversions (1st – 3rd)
Drop-2, spread voicings, all positions
15 Chord Qualities
Maj7, m7, dom7, m7b5, dim7, alt, sus, and more
Integration Options
Lesson Tab
New "Practice" tab within each lesson. Context-specific: the lesson's voicings are pre-loaded. Zero friction for students.
iframe with URL params
Standalone Section
Dedicated "Practice Tools" area in your navigation. For free practice, not tied to any specific lesson. Scalable to future tools.
Subdomain or embedded route
Post-Video Challenge
CTA after the video: "Ready to practice? Test in all 12 keys!" Highest conversion — motivation peaks right after learning.
Overlay / modal trigger
Materials Enhancement
Alongside PDFs in the Materials tab: "🎹 Practice this voicing interactively." Lowest integration effort.
Link with preset params
Harmony Games trains the ear.
Chord Trainer trains the hands.
Harmony Games Unlimited
- ✓ Quiz-based — identify chords by ear
- ✓ Builds harmonic listening skills
- ✓ Theory recognition & ear training
Chord Trainer
- ✓ Performance-based — play the voicings
- ✓ MIDI validates actual playing at the keys
- ✓ Speed drill through all 12 keys
- ✓ Weakness analysis per chord root
- ✓ Works at 2 AM, no live session needed
They're complementary, not competing. Harmony Games confirms understanding — Chord Trainer builds fluency. Together with All the Keys sessions and Guided Practice, you'd cover the complete journey from concept to muscle memory.
Simple Terms
Full functionality. MIDI, progress, all voicings. Zero risk.
Predictable cost. No per-user fees. Scales with your growth.
Open Studio colors, logo, domain. Students never know it's external.
Let's Build This Together
15-minute demo. I'll show you the trainer running with Open Studio branding, walk through the integration options, and answer any questions.
Aaron Pfutzner · Aaron Technologies OÜ · info@jazzchords.app