Demi Lovato arguably has the best set of pipes in the entire Disney alumni set, and she showed them off in a big way. The 'X Factor' judge and hair color chameleon performed three tracks in an acoustic set for the Grammys Headquarters, and she showed that she doesn't need big bands, dancers or background singers to sound fantastic.

Rocking a black blazer, black top, black pants and her new blue hair -- which is now more of a teal -- Lovato delivered the big vocal guns.

In 'Skyscraper,' Lovato's vocal acrobatics and strength earned her rousing applause for what's become her signature ballad. She belted the moving tune beautifully, overcoming the injustices that the poor sound quality of the above video doled out.

She shines even brighter in 'Nightingale,' where she emotes even more truly than before. (Maybe that's because she's said more than once that she's tired of singing the songs from 'Unbroken!')

Lovato closed out her set on an uptempo note, performing a rousing rendition of 'Neon Lights.' Though it's tough to imagine the EDM-inspired song in an acoustic setting, she makes it work -- and she makes it look effortless.

Watch Demi Lovato Perform 'Nightingale'

Watch Demi Lovato Perform 'Neon Lights'