They collaborated on James Corden's chat show last night
If you listened to Billie Eilish before she released her debut album 'When We All Fall Asleep, Where Do We Go?' this year, you might know her song 'Ocean Eyes'.
The track - written by her brother Finneas - is taken from her 2017 EP 'Don't Smile At Me' and before that it was uploaded to Soundcloud in 2015, before she was discovered.
It's a beautiful song, and was made even more beautiful as a duet with Alicia Keys on TV.
Keys was the guest host on The Late Show with James Corden, and with Eilish one of the guests, she played the song as a simple piano number.
Considering how well their voices work together, we'd love to hear the two of them work on something else together.
Watch it below: