'AGT': Simon Cowell's Golden Buzzer & 7 More Auditions From Night 4 (VIDEO)

America's Got Talent Season 15 Night 4 Auditions Best Acts
Trae Patton/NBC

America's Got Talent continued the Season 15 auditions with more singing, dancing ... and participation from the judges.

In the fourth night of the first round, judges Simon Cowell, Sofia Vergara, Heidi Klum (who sat out the second half, after Olox, because she was feeling under the weather), and Howie Mandel and host Terry Crews were treated to more entertaining acts, including one that had Cowell give out his coveted Golden Buzzer.

'America's Got Talent': 8 Memorable Auditions From Night 3 of Season 15 (VIDEO)See Also

'America's Got Talent': 8 Memorable Auditions From Night 3 of Season 15 (VIDEO)

Singers, dancers, and contortionists impressed the judges as auditions continued.

Relive the most memorable auditions of the night below.

Noah Epps

The 11-year-old used dance to help deal with moving around as a military brat. He kicked off the night with a marionette routine that included him twisting and bending his limbs across the stage and was worthy of the standing ovation he received. Mandel said before the act it's hard for one dancer to command the stage but after admitted he was wrong. The judges all said yes.

Luca Di Stefano

The 19-year-old surprised everyone with his voice when he started singing Marvin Gaye's "Let's Get It On." "What an amazing gift you have," Klum told him. (She even thought it was playback at the beginning.) The judges all voted him on to the next round.

WAFFLE Crew

The members of WAFFLE (We Are Family for Life Entertainment) Crew grew up in rough neighborhoods in New York City and spent time in the safe environment of dance centers. They had everyone on their feet after they showed how light they are on theirs with a very fun audition. (Just watch what they do with a shoe and hat.) While dance acts aren't Cowell's favorite, he saw their "energy" and "determination" and called it his "favorite audition so far." Knowing how important this was to them—they wanted to give back to their community—he hit the Golden Buzzer.

'AGT': 9 Must-See Performances From Night 2 of Season 15 (VIDEO)See Also

'AGT': 9 Must-See Performances From Night 2 of Season 15 (VIDEO)

Musicians dominated the second night of auditions.

Nolan Neal

The singer from Nashville revealed his father called to tell him he was going to take his own life before he did; Nolan remembered playing music with him. "I wanted to be like him," he said. AGT was his second chance, and he sang the first song he wrote sober, "Lost." For Vergara, it was personal. "I know very well the sickness of addiction," with her family. "To be here tonight and to hear that song, it gives me a lot of hope about people that are going through [it]," she shared. They all said yes.

Olox

The duo performed The Cranberries' "Zombie" using traditional singing techniques of the people from her village in Siberia. "I've never heard anything like that before," Klum noted, while Vergara compared it to a movie soundtrack. The memorable act earned them four yeses.

Spyros Bros

Marco Angelo, a big fan of AGT, took the stage alone at first, and the diabolo performer didn't seem to win over anyone—until the other half of the act, his brother Mark, joined in from the audience. They wowed all in attendance, including the judges (who sent them on to the next round), by the end. "You guys were incredibly entertaining," Mandel said.

'America's Got Talent': 8 Best Auditions From the Season 15 Premiere (VIDEO)See Also

'America's Got Talent': 8 Best Auditions From the Season 15 Premiere (VIDEO)

From musical to magical acts, the first round of auditions wowed the judges and fans.

Ashley Marina

Cowell agreed with Vergara's suggestion that she come back with new ideas after the 12-year-old singer's renditions of Martina McBride's "Anyway" and Sia's "Opportunity" didn't win him over. Ashley returned with an original song about her father being there for her and received a standing ovation. "That's the biggest gift you can give a father," Mandel told her. "I love this new song, this new you," Vergara added. They had her father join her on stage before they voted yes.

Brett Laudermilk

The entertainer said he liked making people "feel something" with his performance, and he certainly did that with his hard-to-watch sword-swallowing act. It took Vergara three tries to pull the sword out of his throat. He finished with something he'd never done before when he swallowed three swords at once and had each of the judges pull one out, all stemming from Cowell wanting to participate. Unsurprisingly, they voted yes.

America's Got Talent, Tuesdays, 8/7c, NBC