Olivia Rodrigo samples Taylor Swift's 'New Year's Day' on her track '1 Step Forward, 3 Steps Back'.

The 18-year-old pop megastar has released her debut studio album, 'Sour', and after much speculation, it turned out Olivia used an interpolation of the track from Taylor's 2017 LP 'Reputation' on the song from the hotly-awaited record.

As Jack Antonoff co-wrote and co-produced the track with the 'Shake It Off' hitmaker, he also received a credit on '1 Step Forward'.

'Sour' also features the hit singles 'Driver's License - which catapulted the teen superstar to fame - 'Deja Vu' and 'Good 4 U'.

Meanwhile, Olivia recently revealed she would love to feature on Taylor's re-recording of 'Speak Now'.

The music star revealed the US megastar's 2010 record is her "favourite" of her back catalogue, and after the likes of Keith Urban and Maren Morris featured on previously unreleased tracks from Taylor's vault for the re-recording of her 2008 LP 'Fearless', Olivia has put it out there that she'd love to duet with her idol.

Speaking about her dream collaboration, she said: "My favourite Taylor Swift album is 'Speak Now'.I would love to be on a ‘Speak Now’ song. I’m just so excited to listen to them, though. I love listening to the vault recordings and stuff like that.

"I’m gonna own my masters, but I'll listen to songs I’m not putting out and be like, 'Maybe I’ll do a vault thing when I’m Taylor’s Swift’s age.'"

What's more, the singer-and-actress was sent a handwritten note from the 31-year-old Grammy-winner after she skyrocketed to fame, and whilst she doesn't want to "divulge too much" about what was said, Olivia did reveal Taylor told her that "you make your own luck in the world".

She shared: "I don't want to divulge too much because it's really sweet and personal, but she talks a lot about how, I think, you make your own luck in the world.

"And when you do kind things to others, good things come your way. I don't know, she put it so eloquently, and when I say it now ... it's not as cool."

The track-listing for 'Sour' is:

1. ‘Brutal’

2. ‘Traitor’

3. ‘Driver's License’

4. ‘1 Step Forward. 3 Steps Back’

5. ‘Deja Vu’

6. ‘Good 4 U’

7. ‘Enough For You’

8. ‘Happier’

9. ‘Jealousy, Jealousy’

10. ‘Favorite Crime;

11. ‘Hope Ur OK’