I think there are multiple definitions of the word "concert.." To an audience, all of those things are concerts. To a musician, they usually aren't concerts...they're considered a gig or a show... I'm not exactly sure what YouTube thinks is a concert. Several of my videos were made in parks with people stopping to stare, but I don't consider them concerts. If a few thousand people showed up to stop and stare, I'd still not think of it as a concert..lol! : P But..then again..I guess if that many people showed up, I'd better get my blanket performance license figured out and make sure I have my butt covered -- which might lead me to considering it to be more like a concert. I would suspect that YouTube is primarily concerned about the royalty payments and licenses bought to put on the concert, but then also broadcasting it on their site with additional monetization. I still don't really see too much wrong with that, especially if YouTube has agreements in place with the songs played, but there's probably something obvious that I'm missing..