Look up any scale or mode, in any of the twelve keys, and actually hear it played on a keyboard you can tap. Most theory apps hand you a static chart and leave you to imagine the sound. ScaleBook shows the scale lit up across a two-octave piano, spells every note with the correct sharps or flats, plays it back ascending or descending, and then builds the diatonic chords that go with it — so the shape, the name and the sound land at the same time. WHAT YOU GET - 18 scales and modes across six families — major, minor, pentatonic, blues, the seven modes and exotic scales — in all 12 keys - A two-octave piano keyboard that highlights the scale and plays any note you tap - One-tap playback of the whole scale, ascending or descending, with the notes lighting up in time - Diatonic triads for every seven-note scale, with Roman numerals and tap-to-hear chords - An interactive circle of fifths plus a full interval table, so key signatures stop being guesswork - An ear trainer that plays a mystery scale from a random root and tracks your streak, best run and rounds played PERFECT FOR - Piano and keyboard players learning scales beyond major and minor - Songwriters hunting for the right mode or colour for a progression - Music students revising intervals, key signatures and the circle of fifths - Anyone training their ear to tell Dorian from natural minor by sound alone WHY NOT JUST SEARCH IT ONLINE? A search gives you a picture of C Lydian. It does not play it, it does not transpose it to Eb, it does not tell you which chords fit, and it does not work on a stage, on a train or anywhere the signal drops. ScaleBook is fully offline — every scale, every playback tone and every lesson is generated on your device, with no account and no ads. PRIVACY No account, no sign-up, no tracking. Your favourites, ear-trainer stats and tuning settings live only on your iPhone. FULL ACCESS Full access unlocks the complete library — melodic minor, Phrygian, Lydian, Mixolydian, Locrian, whole tone, diminished, Phrygian dominant, Hirajoshi, Hungarian minor and major blues — plus diatonic chord building and the ear trainer. Choose weekly, yearly, or a one-time lifetime purchase. Pick a root note, tap play, and hear what a mode really sounds like. Terms of Use (EULA): https://web-levi.web.app/terms Privacy Policy: https://web-levi.web.app/privacy-policy Questions? tphuc.work@gmail.com