Chris Haston/NBC TheAmerica's Got Talentresults shows can be heartbreaking sometimes, and that was certainly true Wednesday, when results of the second round of the quarterfinals were revealed. HostTerry Crewsannounced that contortionists Unreal, 10-year-old guitarist Bay Melnick Virgolino, and the Leo High School Choir would be moving forward. While that wasn't surprising at all — all of them were amazing — it was a shock that rollerskating aerialists Duo Stardust were left out in the cold. Voters selected which of the acts they wanted to move forward. A fourth contestant, rapper Mama Duke, was already guaranteed to keep her place in the competition, after she earned the Golden Buzzer fromMel B, the judge who held it Tuesday. JudgeSimon Cowellhad been particularly effusive about the Chicago choir, which performed a rousing version of Imagine Dragon's "Believer." Cowell told the group's teacher that she couldn't retire, as had been previously revealed in the pre-taped package before their live performance. "Seriously, you can't," Cowell said, as the teacher cried. "Everyone in life, I believe, does need a mentor, and you are an amazing mentor." He noted that the choir had come back stronger than they'd been in the first round. Alongside Cowell,Sofia Vergarasaid about the choir, "You guys have been one of the best things I've seen tonight." She praised their obvious hard work. Mel B said the group "just lit up this whole entire place," and that she would have given them a Golden Buzzer if she still had one. But the judges had been just as enamored of Duo Stardust. Their difficult, high-flying act left the judges and live audience gasping. The aerialists had noted in a clip that aired before they walked out that they had planned to add another scary element: fire. It wasn't working out, so they made a quick switch. Howie Mandelsaid he wouldn't have known their performance wasn't what they planned to do all along. "I was watching you, and my heart was stopping. The one thing you take away — because it was too dangerous, but everything else you did was okay? — [is] you really rose to the occasion." Cowell said their performance Tuesday was better than their audition — "way better." Taking the fire away, he said, had shown "how crazy, ridiculously hard this is." Both he and Mel B deemed them the best act of the night. Along with the Leo High School Choir, two other competitors received good news. Sign up forEntertainment Weekly's free daily newsletterto get breaking TV news, exclusive first looks, recaps, reviews, interviews with your favorite stars, and more. Contortionists Unreal unsettled audience members as much as the choir had delighted them. Rocker Bay Melnick Virgolino, who's 10, and had shredded on the guitar to Joan Jett's song "I Love Rock 'n' Roll," will also compete in the semifinals. The quarterfinals continue Tuesday, Sept. 2, at 8 p.m. ET/PT on NBC. Read the original article onEntertainment Weekly