“400 Lux” is a slow-burning track with a sunny ambience about driving home with another during a sunrise and enjoying each other.

It’s the second track off of Lorde’s debut LP Pure Heroine. It was debuted on her live tour.

A lux is a unit of measurement for light and illumination, and a sunrise or sunset is about 400 lux on a clear day. The sunny ambience and the lyrics about driving match this tone.

On her 2018 Melodrama Tour, she said the song is a nod to kids in the suburbs.