"I saw it... f---ing crazy!" Eilish -- Billboard's 2019 Woman of the Year -- said of checking out Keys' cover of her "Ocean Eyes" on Instagram. "It was weird because I see a lot of covers and I see a lot of covers of that song and I've also adored you my entire life, so I see a lot of videos of you so I think one thing that is normal and another thing that's normal in my life combined and that was super not normal to see," Eilish said.
Eilish returned the favor by showing Keys a surprise throwback clip recorded a year before "Ocean Eyes" came out, in which the then-12-year-old singer covered Keys' "Fallin'" at a talent show. The adorable clip of a blonde haired Eilish emoting the tune on piano while wearing an American flag cut-off shirt blew Keys away. "We're going to do the next one soon," the fill-in late night host promised, also pledging to take good care of Billie at Jan. 20's Grammy Awards, which she is hosting.
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And they did, in fact, ending the show with a moving, dimly lit duet on "Ocean Eyes," with Keys playing the melody on her convertible piano desk and Eilish perched on the couch.