Music Theory, Refocused
Synchronize what you hear with what you see. When music theory gets fuzzy, come back here — a calm place to see scales, degrees, and spellings clearly.
Training
Sight Reading Bootcamp
Sight reading practice on real staff notation. Practice mode adapts to your level; Survival keeps ramping up the difficulty.
Guide Tone Master
An app for hearing 3rd / 7th guide-tone lines (+ roots) over various chord progressions while confirming them in solfège or pitch names. Supports key changes and playback transposition. Ideal for grasping the skeleton of a tune — the minimal tones that carry each chord's function.
Library
Scale Explorer
Explore scales on treble and bass clefs by degree, interval, Pitch Name, and movable Do. Play scales too.
Chord Explorer
Explore triads and seventh chords on the staff, with inversions and degree labels. Play chords and hear each voice.
Diatonics
See diatonic chords, available tensions, and functional analysis at a glance, key by key.
Music Terms Dictionary
A dictionary of music terms to support you as you learn music. Switch the display language to check Japanese–English and English–Japanese wording.
Tools
Fret & Key Maps
Map scales and chords directly onto guitar, bass, and keyboard fretboards — syncing your fingers with what you see. Click to hear the notes too.
Staff Paper Generator
Generate and download high-quality, customizable, blank staff paper in PDF format for your music theory and practice.
Sound Wave Visualizer
Add tones one by one and visualize in real time how the combined wave and spectrum change.