Util Monster
Free
Explore major, natural minor, modes, and pentatonic scales on a keyboard with their diatonic chords.
Changing the root or scale updates the note list, degree labels, and keyboard highlights together. You can compare Major/Ionian, natural minor/Aeolian, Dorian, Phrygian, Lydian, Mixolydian, Locrian, major pentatonic, minor pentatonic, and blues scales quickly.
The page stacks the 1st, 3rd, and 5th notes from inside the selected scale to show triads. In major, that produces I-ii-iii-IV-V-vi-vii°; in minor and modal scales, it shows which degrees become minor or diminished.
Listen to ascending and descending playback, then repeat the highlighted notes on the keyboard. For writing, compare the scale notes and triads to see which melody tones feel stable over each chord.