The new generation of streaming music services like Spotify, Rdio, and MOG have more music than you could consume in a lifetime. But how much of it would you really want to listen to?

There’s no shortage of great roundups and reviews showing the pros and cons of each service, but they rarely talk specifically about the different music you can find on each. They’ve all built impressive catalogs, but it’s nearly impossible to tell from casual browsing which artists and albums are exclusives for each.

Fortunately, both Rdio and Spotify offer powerful developer APIs, making it simple to compare the two. (Sadly, MOG doesn’t offer an API, so isn’t included.)

For this test, I needed a large set of popular, well-loved albums to test. I used the top 5,000 albums from Rate Your Music, the quirky 11-year-old online community dedicated to rating and reviewing music. These albums span all genres, from klezmer to chiptune, with a total of 2,282 different artists across 70 years of recorded music.

I used the Spotify and Rdio search APIs to look up each album, and checked their streaming availability in the United States. (Rdio uses the IP address to determine country of origin, making it impossible to query other countries. Spotify, on the other hand, returns a list of every region the album’s available.)

Note: The results aren’t perfect. Spotify and Rdio often have slight differences between artist and album names, which can deliver false positives. Let me know if you spot anything amiss and I’ll correct it.

Results

Of the top 5,000, about 44% were available on both Spotify and Rdio. 4.8% of the albums were only available on Spotify, while a further 6.8% were only available on Rdio. Overall, 56% of the albums were streamable on at least one of the services.

Labels are still withholding most or all of the albums from many popular artists. The Beatles, King Crimson, AC/DC, The Eagles, Tool, De La Soul, Peter Gabriel, Led Zeppelin, and Metallica are nowhere to be found, as well as most of the best albums by The Kinks. Music geeks will be sad to discover that Frank Zappa, Coil, Spacemen 3, and Joanna Newsom are all missing, as well. This landscape will constantly shift as labels change their minds; Arcade Fire was added to Spotify yesterday, and more than 200 indie labels left the streaming services last month.

But what about albums that are exclusive only to one service? The results surprised me. Spotify has a reputation for having a deeper catalog, but at least for historic critically-regarded albums, Rdio has a better selection of both popular and obscure artists. More albums in the top 5,000 were available on Rdio, and they offer exclusive access in the U.S. to huge acts like Bob Dylan, Pink Floyd, the White Stripes, and Queen.



Top Exclusive Artists

Only on Rdio Only on Spotify Bob Dylan (12) My Dying Bride (4) Pink Floyd (8) Miles Davis (4) Bruce Springsteen (7) Candlemass (3) Miles Davis (6) Funkadelic (3) The Gathering (5) The Pretty Things (3) Blind Guardian (4) Current 93 (3) Can (4) Darkthrone (3) William Basinski (4) Underworld (3) Iced Earth (4) Katatonia (3) Stars of the Lid (3) CunninLynguists (3) The White Stripes (3) Charles Mingus (2) John Williams (3) Mahavishnu Orchestra (2) Queen (3) The Jesus Lizard (2) Nevermore (3) The Misfits (2) Thelonious Monk (3) Klaus Schulze (2) Charles Mingus (3) John Coltrane (2) Bill Hicks (3) Galaxie 500 (2) John Coltrane (2) Silvio Rodríguez (2) Camel (2) Secos & Molhados (2) Keith Jarrett (2) maudlin of the Well (2)

Note that artists like Miles Davis and John Coltrane appear on both lists because of how prolific they were. Both are well-represented in Spotify and Rdio, but some critically-adored out-of-print albums are unavailable on both.



Top Exclusive Albums

Only on Rdio Only on Spotify 4. Pink Floyd – The Dark Side of the Moon 63. The Zombies – Odessey and Oracle 6. Pink Floyd – Wish You Were Here 104. Candlemass – Nightfall 7. Bob Dylan – Highway 61 Revisited 231. Funkadelic – Standing on the Verge of Getting… 19. Bob Dylan – Blonde on Blonde 288. The Jesus Lizard – Goat 25. The Clash – London Calling 290. The Pretty Things – Parachute 29. Bob Dylan – Bringing It All Back Home 326. The Jazz Composer’s Orchestra – The Jazz Comp… 30. Bob Dylan – Blood on the Tracks 362. Klaus Schulze – X 51. Pink Floyd – Animals 428. Sodom – Agent Orange 85. Bob Dylan – The Freewheelin’ Bob Dylan 459. Danny Elfman – Edward Scissorhands 103. Bob Dylan – Another Side of Bob Dylan 472. Galaxie 500 – Today 107. Bob Dylan – The Times They Are A-Changin’ 494. Current 93 – All the Pretty Little Horses 121. Dr. Dre – The Chronic 502. Secos & Molhados – Secos & Molhados 149. Stars of the Lid – The Tired Sounds Of 515. maudlin of the Well – Bath 164. Camel – Moonmadness 546. Sun Kil Moon – Ghosts of the Great Highway 174. The White Stripes – Elephant 550. Anathema – Alternative 4 175. Bon Iver – For Emma, Forever Ago 618. Darkthrone – A Blaze in the Northern Sky 196. John Williams – Raiders of the Lost Ark 666. The Byrds – Fifth Dimension 218. Popol Vuh – Hosianna Mantra 685. The Gun Club – Miami 224. Jethro Tull – Nothing Is Easy: Live at the Is… 751. Autopsy – Severed Survival 246. Albert King – Born Under a Bad Sign 772. My Dying Bride – Turn Loose the Swans 278. Keith Jarrett – Vienna Concert 775. The Jesus Lizard – Liar 304. Dead Kennedys – Plastic Surgery Disasters 785. Vektor – Black Future 320. Thin Lizzy – Black Rose: A Rock Legend 787. maudlin of the Well – Leaving Your Body Map 331. Magic Sam – West Side Soul 790. Jean Michel Jarre – Oxygene 369. Bob Dylan & The Band – The Basement Tapes 797. 16 Horsepower – Secret South 387. Eric Dolphy – Out There 803. Riverside – Out of Myself 393. Blind Guardian – Live 804. Darkthrone – Transilvanian Hunger 425. Devin Townsend – Terria 846. Nino Rota – Amarcord 468. Strapping Young Lad – City 859. Suede – Suede 489. Pretenders – Pretenders 900. Darkthrone – Under a Funeral Moon

The fact is that both services have done a tremendous job of building the celestial jukebox — with a couple of high-profile exceptions, nearly everything you’d ever want to listen to is available at your fingertips.

Now, one huge drawback of using the Rate Your Music list is that it skews towards older album-oriented music geeks. That’s great if you like Ornette Coleman and Galaxie 500, but not so great if you like Drake and Katy Perry.

Next week, we’ll set the controls for the heart of mainstream music: the Billboard charts, analyzing every charted single in the top 100 from 1955 to the present. This will give us a completely different view of their catalogs, focused on pop singles, past and present, instead of classic albums.

Want more? Ed Summers did his own fascinating deep-dive into Spotify and Rdio uses top album lists from Alf Eaton’s Album of the Year list collection, and published the results on Google Fusion Tables. Also, try Matt Montag’s Music Smasher, a tool that searches Rdio, Spotify, and Grooveshark.