Guitar Strings Oscillating in HD 60 fps

I MADE A VIDEO EXPLAINING THIS EFFECT: This is an unedited video taken from inside my Classical guitar. It still is visible with a steel string guitar, but I feel it looks better on my Classical. The effect seems to only be visible when there is natural light, and when taken from certain angles with high enough shutter speed. Song list: 0:00 - 0:14 Stairway to Heaven - Led Zeppelin 0:15 - 0:32 Tavern (I have a cover on my channel, check it out.) 0:33 - 0:43 Malaguena 0:45 - 1:00 - Florida Georgia Line 1:01 - 1:14 I See Fire - Ed Sheeran 1:15 - 1:24 Let Her Go - Passenger 1:25 - 1:35 Here Comes The Sun - The Beatles