iHeartRadio, the streaming radio platform created by Clear Channel, will be holding a large music festival at the MGM Grand in Las Vegas. The event will happen on September 23rd and 24th and it being billed by the service as “the biggest live music event in radio history.”

According to the iHeartRadio site, the festival will include performances by Lady Gaga, Coldplay, Steven Tyler, The Black Eyed Peas, Kenny Chesney, Alicia Keys, Jennifer Lopez, Carrie Underwood, Jane’s Addiction, Nicki Minaj, John Mayer, Rascal Flatts, Bruno Mars, Sublime, Kelly Clarkson, Usher and Sting. This list will be constantly updated as new acts are introduced all summer.

The entire festival will be streamed on the web and through mobile apps.

If you are unfamiliar with iHeartRadio, they are an online and mobile service that aggregates over 750 radio stations from over 150 different America cities, and streams them for free. The live streams are available at iHeartRadio.com as well as on apps for iOS, Android, Blackberry and Windows Phone.

Not only do they stream live radio, but they also stream “personality channels” like American Top 40 with Ryan Seacrest. They have also recently announced that “custom radio,” much like Pandora, will be launching soon.

In order to promote their fall concert in Vegas, iHeartRadio has started a social media campaign that includes both Facebook and Twitter.

On Facebook, they have enabled an exclusive ticket pre-sale that allows fans to purchase tickets to the event a week before they go on sale to the general public this Saturday, July 16th. All you have to do is “Like” iHeartRadio and you can find out how to get your tickets ahead of time.

After tickets go on sale this Saturday, Facebook will also be the place that people can enter to win a trip for two to the festival. Once again, people will need to “Like” the iHeartRadio page in order to be able to participate.

Ryan Seacrest is doing his part to advertise the event on Twitter, as you can see here –

Here’s some more Twitter chatter about the upcoming event –

Here’s a video about the event, with Ryan Seacrest as your guide –