Listen to Meghan Trainor's Adorbz Mashup of Justin Bieber & Jason Mraz

When it comes to music, Meghan Trainor is not just all about that bass. She’s also about the Biebs, mistletoe, and Jason Mraz.

During a live performance for 1Live radio in Germany, the 20-year-old singer-songwriter got into the holiday spirit with a cover of Justin Bieber’s “Mistletoe.” And to add a little some special to it, she mashed it up with Jason Mraz’ 2008 hit, “I’m Yours.”

Bieber -- a fan of Trainor’s, he recently remixed her debut single, "All About that Bass" -- paid the breakout star a compliment on Twitter.

Of course, this is not the first time the singer has given a song the ukulele twist. She recently performed a stripped-down version of her chart-topping debut single for ET's Rocsi Diaz. Watch the recording session below.