There's a tradition for music-lovers to dig through the crates, but I think one aspect missing from the discussion of reaction videos is how a generation of kids have almost the entire history of recorded music available to them
A couple of times recently my son has asked if I'd heard a particular band or track when I was his age, and I have to explain how seeking out new music involved weekly negotiations with a shop assistant to have them put on albums in a shop when I might only have money to buy one a month.
I wonder if reaction videos are to music videos, what reality television is to dramatic television? It seems as though these strip away the surreal imagery to provide a real(er) human face for music.
Then again, the whole rise of reaction videos suggests to me there are a lot of lonely viewers looking for a sense of connection. The Williams twins (shown in the video above) often have an unguarded and sometimes emotional reaction to some of the material they encounter.