I see yours and I raise mine :P https://aguaviva.github.io/GuitarTuner/GuitarTuner.html https://aguaviva.github.io/GuitarTuner/GuitarTuner.html Each bar is co

I see yours and I raise mine :P https://aguaviva.github.io/GuitarTuner/GuitarTuner.html https://aguaviva.github.io/GuitarTuner/GuitarTuner.html Each bar is correspond to each key in a piano. The red vertical lines are the notes of a guitar played open string. You can use this to tune your instruments and to understand its harmonics too.