Loads of pop stars went to north Wales for Radio 1's Big Weekend.
Around 40,000 fans, including Newsround, went along too to see the likes of Justin Bieber, Chipmunk, Rihanna, JLS, Pixie Lott and lots of others perform.
While we were there we were determined to grab a chat with Justin Bieber and some of the stars. Here's what they had to say...
Justin Bieber chats to Newsround
Bieber Fever truly arrived in Wales with lots of people at the festival wearing Justin T-shirts.
We asked Justin what he thinks of his fans and found out about his tour.
And we even taught him what trainers are!
Joe McElderry tells NR what it was like performing in the Live Lounge
X Factor fans got a real treat when Joe McElderry performed.
We asked the singer what it was like to play at the festival and what he thinks of Bieber Fever!
Joe also told us about his plans for the future.
Radio 1's Aled
Find out what Radio 1's Aled thinks of Bieber Fever
Newsround caught up with Aled from Radio 1's Breakfast Show, who was helping to host the event.
We asked the Welsh radio star what he thought about the festival going to Wales.
He also described what happened when Justin took to the stage!
For more on Justin at Radio 1's Big Weekend click the links at the top right of the page.