Fifth Harmony Perform New Song 'We Knew' From Debut Album [WATCH]: 'X-Factor' Contestants Release Song Days After 'Bo$$'

Fifth Harmony has just given fans reason to celebrate today.

The girl group, made up of X-Factor Alums, Ally Brooke, Camila Cabello, Normani Hamilton, Dinah-Jane Hansen and Lauren Jauregui, have just given us a glimpse into their upcoming debut album today by performing an acoustic version of their new song "We Know."

The girls stopped by the Idolator set last week to perform a stripped down version of their new single 'Bo$$,' and today the news site has just posted another song from their Idolator session.

"This is a song that is on our upcoming album that is coming out in the fall, and it's a really cool a cappella moment where we get to sing, and the melody is so sick, Camila says during her introduction for the song. "And if you're a girl, this song probably relates to you in some shape or form."

The theme for the brand new song centers around being able to know when someone is wrong for you and having the strength to walk away from that relationship.

It features the lyrics, "Every though you are so damn fine, I know I'm better off without you. Even if you cross my mind, I would always have to doubt you. I wont believe a thing you say this time."

The girls perform the song with ease as they belt out their signature sound.

Fifth Harmony's new album will be released this fall.