Pop stars and celebs headed to Bangor in north Wales for Radio 1's Big Weekend Festival.
Behind the glitz and glamour, DJs like Jo Whiley were working hard to speak to all the pop stars backstage and we got to snoop around too!
Welsh rock band the Lostprophets kicked off the Live Lounge set. They were very happy the festival was being held in Bangor for the first time!
Only a few lucky fans were able to see X Factor winner Joe McElderry perform in the Live Lounge, which was filled with chairs made out of tree trunks!
Joe also performed on top of a double decker at the mini-festival, before having a chat with Newsround to tell us about his new album.
After going on stage, loads of the bands and singers hung out back stage in their own private garden with swinging chairs and disco balls!
Kelly Rowland smiles for the cameras backstage, showing off some very funky sunglasses!
Justin Bieber signed autographs for fans after his amazing dancing on the main stage.
He didn't hang around for long, but he did have time for a very quick chat with Newsround to tell us he's loving his British fans!
The best place to be was in the main tent where all the big stars performed. Here's Radio 1 DJ Greg James warming up the crowd for Justin Bieber's arrival...
Cheryl Cole also showed off her moves on the main stage on Saturday.
The crowd loved Alicia Keys' Big Weekend version of her hit song Empire State of Mind - she changed the words to sing 'north Wales' instead of 'New York'!
Florence and the Machine was the headline act on Saturday and closed the day with a bang!