Spotify’s July launch in the US quickly heated up the market for music on demand.  Existing players Rdio and MOG both announced free service tiers last week, where previously they only offered free trials.  And this week, they’re all going to the ball with Facebook.

MOG, in particular, is on fire.  They introduced a slick new HTML 5 app in July, and just debuted a desktop client for the Mac.  Type Spotify vs. MOG into Google and you will get over 350,000 results.  We picked a few of the most thorough and thoughtful reviews to highlight here.

Sound + VisionStreaming Deathmatch: Spotify Premium vs. MOG

You always want what you can’t get.  Al Griffin points out that Europe swooning over Spotify while the US was locked out made the Swedish beauty that much more alluring.

His review divides the battle into six rounds, and awards five of them to MOG, with a tie in the device support category.  Giving the PC/Mac Support category to MOG seems a little odd, since Spotify has desktop clients for both, and MOG is still working on a PC version.  However, MOG does have an excellent web app, while Spotify has none.

Computer AudiophileMOG v. Spotify Part I and Part II

Chris Connaker provides the most thorough comparison of these services that I’ve been able to find, and his focus on audio quality is dear to the heart of MMT.

OS NewsSpotify vs Rdio vs MOG

This one is for all you Rdio fans out there.  Unfortunately, the news isn’t good.  Rdio subscriber Eugenia Loli-Queru looks at all three services, and decides to ditch Rdio.  For him, it’s between MOG and Spotify.  Seems to me that Rdio is destined to become the Sprint to MOG and Spotify’s AT&T and Verizon (or RC Cola to Coke and Pepsi — whatever works for you.)

I have not tested Rdio for two reasons: 1) how much time do you think I have, people?; and 2) from everything I’ve read and heard, Rdio lags behind the leaders in the two areas most important to me: audio quality and catalog depth.

Audio Quality, AirPlay, and Bitrategate

The kbps listed above are the highest available from each service.  You need the premium flavor of Spotify to get 320 kbps streams from the desktop, mobile is capped at 160 kpbs.  Although Spotify says they are working to upgrade all of their tracks to 320 kbps, premium customers are still finding many tracks streaming at 160 kbps.  After a prolonged pause (the upgrades began in 2009), the pace seems to have quickened recently — check out this story for more on “bitrategate”.

MOG has AirPlay built-in to its Mac app, so you can stream to your home stereo from there or from an iOS device using AirPort Express or AppleTV.  Or you can just plug in your iPhone/Pod/Pad to your dock or home stereo to get music in your listening room.

Because Spotify limits 320 kbps streams to it’s desktop client, getting the highest quality audio to your home stereo is more problematic. Unless your computer is connected directly to your stereo, you will need a third-party app such as Airfoil to send audio to AirPort Express or AppleTV over your Wi-Fi network.

I found that MOG streaming over AirPlay produced consistently better audio quality than Spotify over AirFoil.  Of course, neither service will do for critical listening.  But for music discovery or casual listening, MOG sounds better, and gives you more and better options to get their highest quality streams.

One advantage Spotify has over the services is response time.  Tracks begin playing almost instantly, and rarely choke or sputter.  There is a price to pay for this: some of your bandwidth will be used to serve cached songs to other Spotify users.  Spotify’s use of peer-to-peer networking concerns some customers, here’s what it says under “use of computational resources” in the T&Cs:

Spotify has a right to allow the Spotify Software Application and the Spotify Service to utilize the processor, bandwidth and storage hardware on your computer or other relevant device for the limited purpose of facilitating the communication and transmission of content and other data or features to you and other users of the Spotify Software Application and the Spotify Service, and to facilitate the operation of the network on which the Spotify Software Application and the Spotify Service runs.

~ Spotify – Terms and Conditions of Use

Finding your music, or where’s the (arcade) fire?

Both MOG and Spotify have pretty impressive catalogs.  I decided to test them out by building a playlist dedicated to the September harvest moon, and was a bit surprised to find all the songs I searched for on both services.

A little more searching turned up a few gaps on MOG.  I found all of the Goldheart Assembly albums, but “Oh Really” from the So Long St. Christopher EP was missing.  Both services had Under the Table and Dreaming from DMB, but MOG’s album was missing two of the tracks.

WhileI found gaps on MOG, Spotify has some gaping holes.  MOG has had (it’s now being updated) the entire Pink Floyd catalog.  Spotify: one live album from 1995.  MOG has most of Peter Gabriel’s catalog, including the 2010 collection of covers: Scratch My Back.  Spotify: a couple cuts from soundtrack albums. MOG has both 19 and 21 from Adele. Spotify: 19 only.  And so on.

I’m not sure how the track counts are compiled, but I noticed a lot of duplication, and a fair amount of filler in the listings.  I can understand different mixes and remasters showing up as multiple tracks, but MOG lists 40 tracks for “Billie Jean”.  Eighteen are from Michael Jackson, the rest are covers, sound-alikes, and karaoke cuts.  Spotify is the clear winner of the “Billie Jean” battle, with a whopping 71 tracks.

And the winner is…

MOG wins: audio quality, catalog quality, web interface, radio features, music discovery

Spotify wins: integration with local files, catalog quantity, windows desktop, streaming performance

Editor’s Choice: MOG

Big Box of Disclaimers

Your choice will depend on what’s most important to you.  Catalog quality is a subjective issue, so check each service to make sure the music you want most is available.  If you like to listen to music on your work computer but can’t install apps, then Spotify’s lack of a web interface will be a problem.

If Facebook is successful in popularizing these services, then streaming performance could become more of an issue, and Spotify’s peer-to-peer approach gives them a substantial advantage.  For now, I like MOG so much that I have decided to drop my premium subscription to Spotify and become a MOG affilliate.

MOG is currently available only in the US, so that makes the decision easy for a lot of the world.  This article is geared towards US readers, and Spotify’s catalog and features vary by country.  Artists and tracks are continually being added to and removed from each service, and there are multiple flavors of free and premium offerings for both services.