Following Bono's recuperation, U2 embarked on the Innocence + Experience Tour in May 2015, visiting arenas in North America and Europe from May through December. The group structured their concerts around a loose autobiographical narrative of "innocence" passing into "experience", with a fixed set of songs for the first half of each show and a varying second half, separated by an intermission—a first for U2 concerts. The stage spanned the length of the venue floor and comprised three sections: a rectangular main stage, a smaller circular B-stage, and a connecting walkway. The centerpiece of the set was a double-sided video screen that featured an interior catwalk, allowing the band members to perform amidst the video projections. U2's sound system was moved to the venue ceilings and arranged in an oval array, in hopes of improving acoustics by evenly distributing sound throughout the arena. In total, the tour grossed US$152.2 million from 1.29 million tickets sold. The final date of the tour, one of two Paris shows rescheduled due to the 13 November 2015 attacks in the city, was filmed for the video "" and broadcast on the American television network HBO.