Defying Gravity is where Urban shows just how far he’s willing to push the limits of country music. The jubilant "Sweet Thing" leads a funk bassline to an explosive chorus, while "I'm In" starts off with a drum-machine beat and then builds into an arena rock love song. As the title suggests, the Australian singer seems to be always ascending here, but the occasional fall results in tunes as affecting as "'Til Summer Comes Around," a distraught autumn daydream haunted by the sounds of a ghostly boardwalk.