Note Frequencies on Musical Scale
Musical harmonies are created when notes with simple fraction frequency ratios are played simultaneously, as discovered by Pythagoras in ancient Greece. Many harmonies are played using different notes from a major scale. Play different notes from the C major scale to see and hear the ratios of note frequencies from the scale.
This was a project for Advanced Topics in Mathematics II, 2016–2017, Torrey Pines High School, San Diego, CA.
 Wikipedia. "Musical Acoustics." (Feb 28, 2017) en.wikipedia.org/wiki/Musical_acoustics.