This Youtuber places his phone inside an acoustic guitar, then begins to play Metallica’s “Nothing Else Matters” from their self-titled 1991 album with a bright but cloudy sky in the background. Thanks to his phone camera’s rolling shutter effect, the actual waves of the vibrating guitar strings are as clearly visible as if they were on an oscilloscope, says Open Culture.
https://youtu.be/CyHjY5HB21g
