Singer/songwriter talks about writing her new single "Crowded Places," which went on to move TV audiences everywhere when it was featured in the hit HBO series "Girls."

In this exclusive GRAMMY.com interview, Banks talks about writing her new single "Crowded Places," which went on to move TV audiences everywhere when it was discovered and featured by Lena Dunham, creator and star of the hit HBO series "Girls." The song drives an isolated yet self-empowered pulse through a party scene that drifts into Dunham's reverie of a new life in the suburbs in the series' second-to-last episode.

"I was in L.A., I had a session with Jack Antonoff, and I just started freestyling," she explains. "He was playing some chords on the keyboard. …  Most of the verses, I did that in one take, and we listened back and we were like, 'Oh, we can keep all this, it's not all trash.' It didn't really fit on The Alter but I still wanted to find its place in the universe. Lena heard it through him and [it was a] snowball effect."

Read More: Banks: Writing "Crowded Places," Coming Into Her Body