Every note is a hidden chord. Then scales, then chords — let's hear it.
Keyboard
Click a key to hold it · click again to release · or use your computer keyboard
Soundingnothing yet — press a key
Frequency spectrum
Circle of fifths
click a wedge to set the root · each step adds one sharp or flat
Chord builder
pick a root and a quality — hear it as stacked thirds
Waveform
the actual shape of the combined sound
Generatornot connected
1Level
0Score
0Streak
0XP
Exercise
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a…k play · g generate · ↻ replay · ⏭ skip · 💡 hint · esc dismiss
Generator · subagent
The exercise generator is the heart of the course — it produces an endless, level-aware stream of interactive music-theory problems. Connect an LLM subagent (model glm-5.2:cloud, thinking off by default for speed) and it will bulk-brew exercises, cache them by level, and keep you playing without waiting. You can change the model here at any time.