I don't know what it is, but Coachella's second day felt even more crowded and crazy than the first! Audiences kept the energy pumping into the wee hours, and yes, the glow sticks came out. I need a breather after all the excitement, but it's your turn for a taste of the mania. Here are the five big acts that had fans bouncing and clapping all day long (and don't forget to follow me on Twitter for festival updates and celeb sightings — yesterday I snapped photos with Rachel Bilson and Kellan Lutz who was hanging in the H&M tent!).