iTunes Radio competes with other non-on-demand internet radio services, like Pandora. It allows you to pick a seed artist or set of artists and then let its magical algorithms decide what other songs and artists best fit your seed. It then feeds you a stream of music that you can like or dislike along the way, theoretically building a “station” of your favorite music, based on your own tastes.
To access iTunes Radio, all you need to do is launch your Music app with a tap, and then tap on the Radio icon in the lower left. Once there, you can create stations on your own, edit stations you’ve already created, or even listen to iTunes featured stations.
It’s also trivially easy to share your own stations with other folks.