The video below shows a visualization of the physics of music in real-time from the inside of a guitar.
By placing his phone inside an acoustic guitar, YouTuber LuvABullTN, plays Metallica’s “Nothing Else Matters” against a backdrop of clouds and blue sky. After a moment, you begin to see the actual waves of the vibrating guitar strings!
For a further explanation on the physics of visible sound, the video below by Youtube physics teacher Doc Shuster, explains the complexity of different standing wave forms as they relate to harmonics (or overtones). A video, which (when we return to the Metallica video at the top), allows us to have a better understanding of how the strings vibrate differently as they produce different frequencies at different harmonics.
via Open Culture