Little Big Town demonstrated their musical fearlessness once again on a new episode of Greatest Hits on Thursday night (July 28).

The award-winning vocal quartet sang a soulful cover of Alicia Keys' "Fallin'" as part of a new episode of the show, which features contemporary music acts covering classic songs from past eras. Keys scored a No. 1 hit straight out of the box with her debut single in 2001, and went on to win three Grammy awards for the career-making hit. The members of LBT admit it was a lot to tackle.

“This song is vocal gymnastics,” singer Karen Fairchild says in a clip from the show, with her husband and fellow singer Jimi Westbrook adding, “Why we bit this one off, I have no idea!”

Of course, Little Big Town are Grammy-winning artists in their own right, and have built their career around their astonishing vocal versatiity. They turn in a very soulful rendition of Keys' hit that underscores their unique vocal blend and also gives the individual singers a chance to shine.

The group have been on a hot streak on Greatest Hits, which breakout country star Kelsea Ballerini co-hosts with Arsenio Hall. The previous week, they turned in a stunning cover of Oasis' "Wonderwall" that brought a California country vibe to the Beatle-esque song.

Little Big Town have worked in other genres for covers before, and even recently released a pop-influenced project, Wanderlust, for which they collaborated with Pharrell Williams.

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