Stars like Beyonce and Rihanna were beginning to push at pop's walls a little bit, but weren't yet at the place of completely breaking the mold. The EDM boom, and accompanying explosion in festival culture, were still a couple years away. Something big really needed to happen.  It didn't take long for Lady Gaga to prove that she was the asteroid pop music was begging to have crash through it. Debut single "Just Dance" topped the Hot 100 for three weeks in early 2009, and "Poker Face" made h