After the performance show, the contestants told reporters that the Grammy-winning singer spent time teaching them how to use their in-ear monitors, the devices that help tune out ambient noise and help them hear themselves on stage.
"A lot of the struggle that had been going on in prior performances was because we hadn't adjusted to the in-ears," said Naima Adedapo, who had been docked for pitch problems in previous weeks. "Marc Anthony took the time to, one-on-one, sit with us and say, 'Okay, how does this sound? How does this feel?' It added so much."
For Casey Abrams, this week "was my first time trying in-ears and Marc helped us out."
Contestants can choose to have both, one or no monitors. Haley Reinhart said she only uses one, "because I still like that live vibe, but you can tune out different things. I'm used to singing over loud music and not even being able to hear myself, so this was awesome getting feedback and lessons from Marc."
One bit of feedback Stefano Langone hasn't received is from chef Gordon Ramsay, who was in the audience Wednesday and tasted Langone's mother's pasta on the show. "I'm sure that will make my mom happy," Langone said. "When Ryan Seacrest said goodbye to me, he said, 'Gosh, there's lot of garlic,' and I said, 'Hey, man, you have to get a mint now.' "
Among the stars in the audience on Wednesday: Steven Tyler's daughter Liv Tyler, actress Kirsten Dunst, Seacrest's girlfriend Julianne Hough, Chicago Code star Jennifer Beals, Aerosmith guitarist Brad Whitford, Temptations founder Otis Williams and season 9 contestant Casey James.