ET's Kevin Frazier was with Katy Perry as she got ready for the Super Bowl halftime show, which some parent groups are saying might be inappropriate for children.

"I have a couple of tricks up my sleeve," Katy told Kevin, teasing the event. "I can't tell you everything. I'm going to let people just think about it."

What we do know is that Katy won't be the only star in the Super Bowl spotlight.

Lenny Kravitz will also be sharing the stage with Katy during halftime, while Idina Menzel will be singing the "Star Spangled Banner" in her first big performance since catching flack for her New Year's Eve performance of "Let It Go," where she failed to hit some notes live.

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In response to her critics, Idina posted an old interview of hers to Twitter, which read in part, "There are about three million notes in a two-and-a-half-hour musical; being a perfectionist, it took me a long time to realize that if I'm hitting 75 percent of them, I'm succeeding. Performing isn't only about the acrobatics and the high notes: It's staying in the moment, connecting with the audience in an authentic way, and making yourself real to them through the music. I am more than the notes I hit."

"It's warmer here, let's just say that," Idina said about how she expects her Super Bowl performance to go. "I will be singing 100 percent live."

Jordin Sparks, who sang the "Star Spangled Banner" at the Super Bowl in 2008, gave some inspiring words to Idina.

"You're absolutely incredible. Just breathe," Jordin said. "Just breathe before the anthem and you'll do fine. You'll be amazing. And just soak it all in, because it goes by really fast."

Super Bowl XLIX, which pits the New England Patriots against the Seattle Seahawks, airs Sunday, Feb. 1 on NBC.

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