Doing a Dave is where somebody takes control of the music, plays progressive songs that are boring as fuck e.g BT but claims they are "classic" and was once played at the start of a set.
To cap it off the person doing the Dave will only play 20 seconds of a song before going off on a tangent to a totaly different song.
For fucks sake this guy is doing a Dave, I want to hear a whole song not just 20 seconds of it