Any reason some of these questions are worded in the past tragic tense? It makes it sound like the Jonas brothers and Lady Gaga are all deceased, that Coldplay broke up, and that Shakira's hips suddenly started lying at some point. (Kudos on the wording of the Justin Nieber question though! Too bad you couldn't have situated HIM squarely in the past tense.)
It was "big" in the sense that it got rave reviews and audiophiles gush over it. Their following album, the Suburbs, was a little bigger and won Album of the Year at the Grammys. Certainly not a smash on the level of the other artists named, but definitely fair game for trivia, I think.
Dubstep = Dub Reggae (Jamaican) + 2 Step garage (not Jamaican)