Billie Eilish dominated the music landscape this year with her monolithic hit ‘bad guy’. In a new interview with Rolling Stone, Billie and her brother — producer wunderkind FINNEAS— broke down how they crafted the song in explicit detail.

As the fine folk over at Pedestrian pointed out, there is a little Australian easter egg in the track that seems to have flown over all of our heads. The pulsating hi-hat that dominates the chorus of ‘bad guy’ is actually a sample of the ‘doop doop’ of a Sydney pedestrian crossing.

Eilish took a sample of the sound when she was down under for Laneway back in 2018.

“My mom and I went for a walk in Sydney, we were like across the street from the hotel,” Billie explains. “The crosswalk was this little, like, you press it and it’s like ‘doop…doop’ and I was like that’s hard! That’s the sound that it makes when you have to wait.”

When Billie registered the bizarre tonality of our traffic lights, she took out her phone and recorded it and saved it under ‘Grart’ in her phone. You can watch Eilish and FINNEAS break down the song below.

Earlier this month, Billie Eilish released a limited edition live LP through Jack White’s Third Man Records. The record is a direct-to-acetate recording of al 11-track acoustic, invite-only set that Eilish played at Third Man Records in Nashville in November. It features a bunch of her most adored hits, like ‘bury a friend’, ‘bad guy’, and ‘ocean eyes’.

The record was pressed on two variants, a green vinyl — available at the Nashville and Detroit stores, and an ultra-limited black & blue split, featuring a splatter artwork by Eilish herself, available exclusively at the Nashville joint.

There has been no word yet as to whether fans can expect a wider release of the record.