Shaky Knees Treefort Where: Atlanta When: May 3-5 The headliners: Beck, Incubus, Cage the Elephant, and Tame Impala Why we're excited: Artists like Cage the Elephant and Tame Impala have such catchy songs, everyone will probably be singing at the top of their lungs. See the full Shaky Knees Treefort lineup. Image Source: Getty / Erika Goldring