Open radio streams in iTunes
The Radio function in iTunes lets you browse stations but it won’t let you search for one. If you know a station that shares a music stream, you can open it directly in iTunes.
Find a stream
Google for radio streams and find playlists that end with .m3u. Copy the stream address to your clipboard.
Open in iTunes
In iTunes go to Advanced > Open stream (CMD+U) and enter the address. For your convenience, you can drag the item from the main grid to your playlists for later listening.