Billie Eilish shares new single 'Therefore I Am'.

Billie Eilish has shared a new single, 'Therefore I Am', alongside an accompanying self-directed music video that was shot in the deserted Glendale Galleria mall.

The tongue-in-cheek song, which plays on the phrase, "I think, therefore I am,” was written by Eilish and her brother Finneas, the latter of whom produced the song.

About the song, Eilish told Zane Lowe: "It [“Therefore I Am”] feels like me. The rest of them also feel like me but this one is more like—if I think about it from an outside perspective, this one, I’d be satisfied, you know, if I was a fan. This song is very, very up for interpretation. I’m curious to see what people get from it and also what they feel when they hear it. Yeah, it’s a little mean, a little bit. It [the song] was very fun to complete. It was fun to record, especially, because, I feel like you can hear it. I feel that I sound very, like, I’m just fucking around. I’m just joking and shit. You know that, “Stop, what the hell are you talking about?” It’s like, come on. It’s so real and natural and don’t take me seriously, you know? I love it."

Watch the 'Therefore I Am' music video below...