After taking a page from the David Bowie-shock-tactic handbook and releasing a surprise self-titled album Friday at midnight, Beyoncé returned to her rightful place on the stage. And, when her Mrs. Carter World Tour stopped in Chicago this weekend, it tested out her highly buzzed-about new material. "I’m gonna sing you a song, which is a brand-new song," she teased the rhapsodic crowd. "It hasn’t even been out for 24 hours. I’m gonna sing this for y’all because it was written for y’all." Before launching into the track, "XO," she added, "This is the first time, something I’ll never forget." Fortunately for the Internet, a fan captured the milestone on video, ensuring we will never forget it, either. Note the impressive call and response going on here — 'Yoncé's fans are nothing if not feverishly committed. Check out her first performance of the new material below. Something tells us this is just the beginning!