Luckily for her, Levine then joined her onstage to sing a karaoke rendition of Maroon 5's 2002 hit "This Love." We were there and captured this video below of the touching, memorable moment.
Levine and Frederick both slayed the song. It's no surprise the crowd went wild at the end of the performance.
It's safe to say Frederick is a huge fan of Levine. Her Twitter bio describes her as the "Official 13th member of #TeamAdam (#TheVoice)" and "@adamlevine's number one fan." She took to Twitter to share her reaction to the spontaneous duet.
According to her personal website, Frederick "has gone to at least one concert on every Maroon 5 tour since 2011." Now that's dedication! We're sure she'll remember this bucket list moment forever.
Before you go, check out our slideshow below.
And you'll see personalized content just for you whenever you click the My Feed .
SheKnows is making some changes!