Paramore's adamantium-plated self-titled album came out more than a year ago, but only recently did the "Beat It" meets "Like a Prayer" gospel-funk of "Ain't It Fun" crack the top 10 of Billboard's Hot 100, making it the Nashville band's biggest hit to date. Hayley Williams & co. played a full-throated, crowd-pleasing rendition of that song this morning in New York on Good Morning America (above). That led (below) into their previous biggest hit, "Misery Business" from 2007's Riot! — joined exuberantly by splits-doing fan Christian Brown, who previously came up onstage with the group at Madison Square Garden — and Paramore's power-pop gem "Still Into You," which we're still into. "Hey p-more family, @GMA folks have reported that this was one of their best crowds ever," Williams tweeted. "In the rain, no less!" Read SPIN's recent Paramore interviews.