Heidi Klum revealed she’s learned a lot on the show over the years, especially from Simon Cowell as he appears to “have an ear” for music.

The supermodel, who is joined by judges Simon Cowell, Mel B and Howie Mandel, says she has learned to always be honest, even if it means disappointing fellow judges and even the audience.

Heidi, who joined the program back in 2013, told Billboard: “Over the years I’ve learned that you should always give your honest opinion, even if that means disagreeing with the other judges or getting booed by the audience!

Everyone has their own thoughts on each performance and it’s important to share those. Simon hasn’t really changed the way I judge, but sometimes he does change my vote from a no to a yes.

When there are singers on stage, Simon will have them sing a different song if he doesn’t think the one they chose is the right song. He has an ear for that, so when they start singing that second song, I go, ‘Oh my gosh,’ he got something out of them that we didn’t hear before.”

She also took the chance to show off her singing skills in the America’s Got Talent Holiday Spectacular, which aired on December 19th. The catwalk icon shocked viewers as she sat on a big candy cane while dressed in a scarlet Christian Siriano gown.

Klum – who was previously married to singer Seal – then performed with 21-year-old Sal Valentinetti, which was also her golden buzzer pick on the last season. Their duet eventually earned them a standing ovation from Simon.

She said of the performance: “I am so proud of him! He truly is one of a kind, and he is going to do big things in the future. The producers of ‘AGT’ thought it would be fun for us to sing together for the holiday special, and I am always game to try! So we have (done) a fun little number. I love singing, but I’m not a singer like Sal!”