If your favorite Aaliyah album was her Jive debut Age Ain't Nothing But a Number, you're fine, as that LP (featuring Billboard Hot 100 top 10 hits "Back and Forth" and "At Your Best (You Are Love)") is available on most streaming services. But if you prefer her post-R. Kelly period -- as most fans do -- you're out of luck, as 1996 follow-up One in a Million and her 2001 self-titled third album are widely unavailable, thanks to the distribution hell of the now-defunct Blackground Records. (Certain albums by Tank, Toni Braxton and Timbaland & Magoo -- and perhaps most upsettingly, the Romeo Must Die soundtrack -- find themselves in similar limbo.)
Bikini Kill
The digital-only soundtrack to The Punk Singer, documentary about Riot Grrrl queenpin Kathleen Hannah, has made a handful of songs by the Olympia punk gods accessible to streaming, but otherwise, Bikini Kill's EPs and albums are totally absent. "It's just a crappy deal for the bands, exposure or not," bassist Kathi Wilcox explained to Verge in 2015. "I know a lot of people really love those streaming services, and they say they hear about a lot of bands they would otherwise never hear, but how much of that translates into financially supporting those bands?”
De La Soul
Paperwork has held up the legendary rap trio's Golden Age material, including classic LPs like 1989's 3 Feet High and Rising and 1991's De La Soul Is Dead, from reaching streaming services. “Unfortunately, a lot of the earlier stuff we did on Tommy Boy [Records], from what we understand, a lot of the legal language that needed to a part of the contracts between ourselves, the owners of the master and the publishing, I guess it didn’t include the world of digital,” Kelvin "Posdnous" Mercer told Bloomberg in 2015. “So when dealing with that it took a lot [and] is taking a lot of time to reach out to these different people." At the very least, the group's last few albums (including this year's excellent, Kickstarter-funded and the Anonymous Nobody...) were post-Tommy Boy, and thus accessible on most services.
King Crimson
The complex time signatures and double-digit-minute lengths of King Crimson's most famous songs are non-existent on demand -- you can't even find a live version or a soundtrack one-off from the prog-rock greats on Spotify or Apple. Legendary guitarist and King Crimson leader Robert Fripp has been a long-time critic of digital and streaming, doing the math when a couple songs of his were briefly made available on Spotify, and asking in an incredulous 2009 Internet diary entry: "Is this seriously being presented as a future for the industry?”
The KLF
The notorious top 40 anarchists who literally wrote the book on conning the music industry are perhaps the least-surprising holdouts of the streaming age, having publicly deleted their back catalog and retired from recording nearly a quarter-century earlier. Strangely, the group's material -- including their standard-bearing early-'90s ambient house LP Chill Out -- briefly appeared across digital and streaming services in early 2013, but was removed barely a day later.
Yoko Ono
The art-pop icon can be heard on streaming through her collaborative releases — remix albums Yes, I'm a Witch and Yes, I'm a Watch Too, as well as John Lennon co-projects like Double Fantasy and Plastic Ono Band. But outside of some compilations and one-offs, solo Yoko is still a no-go for most services, including her influential early-'80s albums Season of Glass and It's Alright (I See Rainbows).
Suede
The first breakout band of the Britpop era had their '90s and '00s material available on Spotify and other services until a couple years ago, when it was pulled without explanation. (Billboard has contacted the band for comment but had not heard back as of publishing.) You can still listen to the group's delectable recent works, 2013's Bloodsports and this year's Night Thoughts, as well their self-titled debut and the 20th Anniversary Live performance of 1994 artistic high-water mark Dog Man Star -- all under their U.S. moniker "The London Suede" -- but not the original release of that album, or their hit-stacked 1996 effort Coming Up, among others.
Tool
The alt-metal enigmas of the '90s and '00s have gone platinum with each of their four studio albums, but if you want to hear them, you still gotta track down physical copies -- the group has continually resisted digital distribution, and is unavailable for on-demand listening. There does appear to be one song of the band's available on Spotify, but don't be fooled by the plausible title: "Anti-Nuclear Bacteria" is actually a deep-house track by a Japanese DJ named TooL.