I've got an old friend living in Seoul now, she says karaoke clubs are still very popular there, that Friday night after work binge drinking usually happens to karaoke.
The YT thing: I used to go to a first Fridays party in NYC with some 2600ers at a geek couple's west vill apt, and YT was the thing. Two monitors, one mirrored to the flat panel TV, with one YT vid playing on-deck, the next getting cued on the second monitor; swap windows when the track ends.
Sometimes it was music, live in concert tracks too, but more often it became viral funny stuff like cat videos, Russian dash cam footage of car wrecks, plane crashes, Ron Paul speeches (popular with that crowd but what a buzz kill) -whatever was on ppl's minds at the time. Audience participation in vid selection was a thing.