Swift collaborated with other artists during the 1989 era. She performed "I Saw Her Standing There" and "Shake It Off" with Paul McCartney at the Saturday Night Live 40th Anniversary Special after-party,[238] and joined Kenny Chesney to sing "Big Star" on the opening night of his Big Revival Tour in Nashville.[239] She also accompanied Madonna on guitar for an acoustic performance of "Ghosttown" at the iHeartRadio Music Awards.[240]