Billie Eilish is a fan of Katharine McPhee.
The 18-year-old singer has admitted she has been a fan of Katharine's song 'Over It' since she was 12, after she heard it for the first time when her dad, Patrick O'Connell, played a 40-second clip of it at home.
Speaking during an appearance on her 'me & dad radio' show for Apple Music - which she stars on with her father - Billie said: "I think I was 12 or 13 ... and dad was playing this 40-second version.
"It was the chorus, that's all there really was, and the chorus has this beautiful melody, one of those melodies that makes you feel something. I'm such a melody w****. I just ... God, melodies really get me, and this one really got me, and got dad too.
"We found the song, and it's been one of my top songs for years. I just think about my dad the whole time because we found it together. It's a great message going on, it's gotten me through some stuff when I was a little sad 13 year old upset about all the wrong things. She speaks only facts in this song."
And Katharine herself has been left stunned by the confession.
She took to Twitter to write: "who knew @billieeilish was as big of a stan of me as I am of her WHAT THE HELL
"this is such a sweet story! I am honored!! thank you @billieeilish. (sic)"
Billie's love for Katharine comes after her mother, Maggie Baird, revealed the 'Bad Guy' hitmaker had an obsession with Justin Bieber that was so severe, she considered putting Billie into therapy.
Maggie told her daughter: "I just want to say, we did consider taking you to therapy for how incredibly ... you were in so much pain over Justin Bieber.
"It was so intense, it caused you so much pain!"