Jem Aswad Senior Music EditorFoo Fighters, Post Malone, Tyler, The Creator, Miley Cyrus, DaBaby, Marshmello, Illenium, Megan Thee Stallion, Roddy Ricch and Journey — yes, Journey — are the top-billed headliners for the Lollapalooza 2021 festival, taking place July 29-Aug.