Is Pandora an app?
I downloaded is as on app on my ipad but you can also log in to pandora.com from your desktop and listen to it there. There's a free version which plays a 30 second commercial after every five songs and a commercial-free (and supposedly better-performing) subscriber version for $3.99/month. I use the free version but I'm so happy with it I just might bump up to the subscriber version.