While Finneas and Billie Eilish will always be siblings, they may eventually not always be producing music together. During a recent interview with Guitar.com, Finneas said he’s been letting go of the reins some when it comes to music production for Eilish and helping her learn how to produce on her own.

Billie Eilish and Finneas have been a package deal since day one. The siblings’ musical kismet has worked out pretty well so far, netting them billions of streams, two Oscars and Golden Globes, nine Grammy Awards and three Billboard Music Awards, among many others.

He plays the heavily manipulated audio (a “vocal chop,” as Eilish calls is), and Eilish asks Finneas if he has the original sound from which that came. He did and he played it, and it was Eilish singing,