Billie Eilish & Finneas

1466.594 - 1492.59 Terry Gross

So I want to play that song because, Billy, you were talking earlier about how when you started recording when you were 13, you were much younger, your voice was different. But, Phineas, I want to ask you first. I think not many teenage boys would think like, oh, I want to hang out and write songs with and record with my younger sister who's 13. What made you think, oh, Billy has to sing this?