Good news for music enthusiasts: Spotify's streaming music service is now free. The Spotify app has always been free, but you had to pay $10 per month for the opportunity to listen to on-demand music. That meant that you could request any particular song from their catalog. This, of course, was different from services such as Pandora and iTunes Radio, which let you indicate your favorite music but then stream similar music rather than the particular favorite you identified. Spotify's new free service for the iPhone falls somewhere in between. You can identify a particular artist, album, or playlist, but then Spotify streams the music in "shuffle mode," meaning that you get your favorite music but not a particular song at a particular time. The playlists available include those you've put together as well as playlists your friends have created.
The terms are different if you have an iPad. You can actually play on-demand songs for free. Whether you listen via the iPad or the iPhone, you'll have to listen to an ad every five or six songs,.
In addition, there's a premium version still available for $10/month that lets you listen to music on demand on your iPhone or iPad, without occasional ads, and at a higher quality. Plus, you can download songs for listening offline. A great article on Mashable clearly explains your options.
The free shuffle mode for the iPhone may not let you listen on-demand to particular songs, but it's way ahead of the other services in that you can identify a particular artist, and then it will stream only music of that artist. The only hitch is that the songs are shuffled. Similarly, you can listen to a playlist of your favorite music that you've created, but Spotify shuffles the order. There are some rules for playlists: they must have at least 20 different songs from at least 3 different albums.
The app has lots of other features, including the ability to create playlists and a feature, called Discover, that helps you find new music based on your favorite songs and artists.
So why did it take Spotify so long to come out with a free service to compete with the others? A great article on CNET explains the complexities of the licensing details and gives interesting background information about Spotify, which is based in Sweden.
Overall, this seems like another excellent option — and one that has features not available from the likes of iTunes Radio and Pandora.