Headliners such as Ed Sheeran, Taylor Swift and Sam Smith are preparing to descend on Swansea for BBC Radio 1's The Biggest Weekend.
Singleton Park will host two days of live music as part of the festival which also features Florence and the Machine, Jess Glynne and Liam Payne.
Tickets for the event on Saturday and Sunday sold out quickly and more than 52,000 people are expected to attend.
A week-long fringe festival has been running in the build-up.
Welsh singers and bands will also be given a platform to perform.
Radio 1 DJ Scott Mills said: "Any second now the whole of Radio 1 is going to be here and we are going to take over, basically. I am so excited.
"I think this is the biggest line-up we have had. You don't get all of those superstar acts on one bill like this, like Sam Smith, like Sean Mendez, Ed Sheeran, Taylor Swift.
"Normally we have one of those, and just to have that many is incredible. Swansea is not going to know what has hit it."
Swansea is one of four UK cities hosting concerts as part of The Biggest Weekend, alongside Belfast, Coventry and Perth.
Welsh acts including Astroid Boys and Rachel K Collier will perform on the BBC Music Introducing stage.
Other Welsh performers have been given opportunities to perform during the fringe week, including Swansea-based singer and loop artist Ben Luc.
He said: "I've been performing in Swansea for five or six years, and I'm currently studying here. Swansea is a great place to be a performer.
"This is a really good thing for artists like myself, and Swansea as a whole, because it is shining a light on the good things happening here, and the creative scene in Swansea."
A number of roads around Singleton Park will be closed during The Biggest Weekend.
For fans travelling to the event by car, Swansea Council will be operating a park and ride service from its Fabian Way site, while some car parks will be available outside the area affected by road closures.