All the major on-demand streaming music services -- which let you listen to any song in their catalog at any time, operating basically like iTunes in the cloud -- feature some crucial core similarities. The services discussed in this section all use a tiered pricing model: each offers a free ad-supported level, a $5 tier that removes the ads and a $10 premium tier that typically ups the audio quality, introduces device support for tablets, smartphones and home electronics, and adds an offline mode for listening to music when you're away from the Internet. Most also offer basic radio-style functionality, although experts say their attempts pale compared to dedicated radio-style streaming music services like Slacker Radio and Pandora (discussed in the next section of the report).
Two services consistently bubble to the top of most expert reviews: Spotify and MOG.
MOG (*Est. $5 and up; free version available) doesn't have Spotify's marketing might, but it garners just as much praise from reviewers -- and MOG trumps Spotify in several head-to-head roundups. MOG's 14 million-plus music tracks (at press time) don't quite match Spotify's 15 million, but reviewers say that MOG actually carries some well-known artists that Spotify doesn't, such as Pink Floyd. Most report having better luck finding tunes on MOG than Spotify.
Reviewers report that MOG's music flat-out sounds better than Spotify's, too. While Spotify limits 320 kbps audio streams to Premium subscribers, that's the default bitrate for MOG, and reviewer after reviewer says that the audio quality is top-notch, especially when streamed into home audio setups via a Roku box or Sonos audio system. (See our review of the Sonos system in our wireless speakers report.) "MOG is in fact worthy of being played through high-end equipment," John Grandberg writes at the InnerFidelity.com audio enthusiast website. The mobile apps limit songs to 64 kbps by default, but you can choose to override that setting and stream at 320 kbps if you're on a Wi-Fi or 4G network.
Speaking of mobile apps, experts say that's another area where MOG shines. Tested.com compares MOG's Android app against Rdio and Spotify's offerings, and TechCrunch.com conducts a similar test with the same services' iPad/iPhone apps; MOG comes out on top in both roundups, thanks to a polished user interface, unlimited offline caching capabilities and high-quality 320 kbps audio streams. MOG earns similar praise for its attractive web-based interface on PCs, although critics note that its social media and sharing options are much more limited than Spotify or Rdio's.
MOG's radio function, a rarity for an on-demand service, also earns kudos. After picking an artist, you move a slider across a bar at the bottom of the screen. At one end of the bar, you'll only hear songs from that artist; sliding toward the opposite side gradually introduces more and more music from similar artists. Reviewers love it.
There are a couple of downsides to MOG, however; unlike Spotify, it can't integrate your personal music collection into its catalog, and its free version doesn't offer unlimited listening, although you can receive additional air time by using MOG's social functions. However, MOG's social sharing options are largely limited to sharing tracks over Twitter and Facebook.
Spotify ($5 per month and up; free version available) attracted a lot of media attention when the service launched in the U.S. in July 2011, after dominating the European market since late 2008. But the service has more than just a marketing blitz in its corner; Spotify has one of the largest streaming music catalogs around, with 15 million tracks available at launch.
The sheer number of tracks available means that almost everybody can find something to listen to regardless of their musical preference, but there are a couple of puzzling gaps in coverage. For example, Pink Floyd's collection isn't available on Spotify despite being available on competing services (including MOG), and Bob Dylan's music was only recently added to the streaming music service. Spotify has been diligently plugging the holes since launch, however, so some of the missing artists mentioned in initial reviews have since been included in the service's catalog. The Spotify client can also integrate music stored on your own hard drive, whether the service carries it or not. You can also build custom playlists.
Audio quality-wise, Spotify falls in the middle of the pack, with only $10 Premium subscribers receiving access to high-quality 320 kbps bitrate streaming. Desktop users get 160 kbps, while mobile listeners stream at 96 kbps. Reviewers say the mobile apps are basic and clunky but get the job done, and they like that a whopping 3,333 songs can be cached for offline use.
Spotify allows developers to create apps for its desktop client, some of which add useful functionality to the service; for example, a Rolling Stone app provides music reviews, a Last.fm app generates radio-style music playlists and the TuneWiki app provides you with the lyrics to streamed songs.
Users can share songs and playlists with friends in the Spotify client itself or via Internet links, Windows Messenger, Twitter or Facebook. That last note has been a point of contention for the service; shortly after launch, Spotify began requiring new users to sign up using their Facebook accounts, which upset reviewers and users alike. If you don't use Facebook, you can't sign up for Spotify.
Experts note a few other flaws, as well: They dislike that Spotify uses a stand-alone client rather than a web-based interface, and they find the look of the client unattractive and cluttered, albeit straightforward. Spotify isn't as good as its competitors at helping users discover new music. The free version also runs ads more frequently than others, but it's the only on-demand service that allows users to listen to an unlimited number of tunes for free.
Rdio (*Est. $5 per month and up; free version available) is an on-demand streaming music service that resembles MOG and Spotify in a lot of ways -- right down to its 15 million-ish available tracks -- but with a stronger focus on social-based sharing and music discovery. In fact, users are prompted to begin following other Rdio subscribers before they are even given access to music after signing up. Users can listen to playlists based on what their friends are listening to, send recommendations to others and even work together to create collaborative playlists.
If social music discovery is your passion, experts say Rdio is the streaming music service for you; if not, most say MOG or Spotify are slightly better options. Rdio's desktop, web and mobile clients are polished and functional, experts say -- just not quite as polished and functional as MOG's (although Rdio is more colorful). The free version doesn't run ads, but allows you to listen to only a small amount of music monthly.
Rdio isn't exactly upfront with its audio quality, either. The company's FAQ page says it's constantly tweaking bitrates, but representatives have claimed that the service streams in "up to 256 kbps" in the site's help forums. Nevertheless, reviewers say that Rdio's audio quality doesn't come close to matching MOG's top-notch tunes. The quality is especially bad on Rdio's mobile apps. "At times things sounded acceptableÉ but not once did I feel it would pass as 'CD quality sound,' " John Grandberg writes at InnerFidelity.com.
Rhapsody (*Est. $10 per month and up) , one of the oldest streaming music services around, is more expensive than its newer competitors, who offer $5 web-only subscriptions. That's widely cited as a negative, and most experts also say Rhapsody doesn't offer as polished a service as its competitors. Although the service garners a few recommendations -- mostly in somewhat older reviews -- the majority consensus is that Rhapsody simply doesn't offer much that makes it stand out from the rest of the crowded on-demand field. "Rhapsody has been around for a long time, and it shows," Ryan Whitwam writes in a Tested.com roundup of streaming music apps for Android phones.
One area in which Rhapsody does stand out is its expansive support for a wide number of home electronics. Not only is there support for Sonos players and the various makes and models of the Logitech Squeezebox, but also for a very large number of home theater receivers from several top manufacturers.
Rhapsody's 14 million tracks certainly compete with catalogs offered by the other top streaming music services, but music streams at a relatively low 128 kbps, which disappoints experts. The mobile app is slow and clunky, and its streaming tops out at 64 kbps. "The audio is noticeably inferior," Adrian Covert writes at Gizmodo.com. However, Rhapsody maintains a large downloadable music store where you can purchase individual songs and albums at 256 kbps quality.
Covert doesn't like Rhapody's user interface, either. "Streaming Rhapsody from the web sucks," he writes. "Everything from the page design to UI elements to overall responsiveness sucked (it also borderline fails to work in Chrome)." The poorly designed interface is part of the reason Rhapsody comes in last in a three-service roundup at MacLife.
Finally, there's Grooveshark ($6 per month and up; free version available) , an intriguing on-demand streaming music service with tons of tracks and users, a totally free -- and unlimited -- ad-supported web-only version and a heavy dose of social sharing features. Unfortunately, experts report that Grooveshark's reliance on users to upload music introduces both unevenness and questionable legality to the streaming music service.
While Grooveshark offers high-quality tracks from several indie music labels, it has only signed a licensing contract with a single major U.S. label, EMI. Normally, that would mean that Grooveshark would have much less music available than other streaming music services, but experts report the inverse is true: Grooveshark carries the most songs any reviewer has ever searched for.
That's because Grooveshark allows users to upload any music files they own to the company's cloud servers; those songs then also become available for other users to download. According to Grooveshark's policies, users can only upload songs they hold the copyright to, but that technicality is largely ignored in practice, and critics say Grooveshark doesn't rush to remove infringing files unless prompted to by the actual copyright holders. In fact, CNET reports that emails from Grooveshark's CEO prove that Grooveshark's business model is based on using the labels' music without paying licensing fees.
Grooveshark's questionable legality has led to its apps being pulled from both Apple's App Store and Google's Play Store. An app is available for jailbroken or rooted smartphones, however, though you'll need a premium subscription. The site is also being sued by the major U.S. recording labels. It's worth noting that individual users who upload and download music they don't hold a license to may also be opening themselves up to legal repercussions down the road. The company's German branch recently closed and Grooveshark began discontinuing its free service and charging users $4 a month in several countries around the world in 2012. (The U.S. is thus far unaffected.)
On a more practical level, Gizmodo.com's Adrian Covert reports that the reliance on user uploads results in occasional gaps in Grooveshark's music library and drastically varying music quality. "You might only find one stray song from an artist at 320 kbps, or you might find an entire catalogue at 128 kbps," he writes. Both he and PCMag.com's Jeffrey Wilson find the interface a bit clumsy, as well.
Despite that, the mixture of free tunes, a large music library and the ability to upload your personal music files to the cloud wins over users at Engadget.com and Lifehacker.com, as well as Mark Harris, About.com's digital music guide. If you can overlook the varying song quality and dubious legality (don't say we didn't warn you!), Grooveshark could be worth trying out.