1. 

Troye Sivan appeared in Ariana Grande's music video for...?

2. 

Where did Shawn Mendes and Niall Horan first meet?

3. 

What was the name of Post Malone's 2016 collab with Justin Bieber?

4. 

Which Jessie Reyez track put her on Billie Eilish's radar?

5. 

What year did Taylor Swift and Selena Gomez first become friends?

6. 

Lady Gaga and Elton John collaborated on which 'Chromatica' track...?

7. 

Demi Lovato and Sam Smith collaborated on which track...?

8. 

How many tracks have The Weeknd and Lana Del Rey worked on together?