tonejs can be used for playing sounds e.g. scales, chord, mic loop, metronome, etc. Also an interactive keyboard.
tonal app for scales, keyboard, sheet music, circle of fifths visualizations, keyboard sounds
sharp11 for keyboard visualization, sounds
teoria, a music theory library
vex fretboard, a clean guitar fretboard visualization based on paper.js
References/inspiration
tonejs can be used for playing sounds e.g. scales, chord, mic loop, metronome, etc. Also an interactive keyboard. tonal app for scales, keyboard, sheet music, circle of fifths visualizations, keyboard sounds sharp11 for keyboard visualization, sounds teoria, a music theory library vex fretboard, a clean guitar fretboard visualization based on paper.js