For the past four years, Spotify has been omnipresent in the music world. But the streaming service isn’t complete, as several prominent artists have some or all of their catalogs missing. Apple Music was unveiled yesterday as the latest entrant into the streaming wars, and though questions remain about the service, it has the potential to completely upend Spotify and the rest of its competitors. Anything that’s in the iTunes store is said to be available on Apple Music, which would include many of those artists not on Spotify. As of Monday night, Apple was still negotiating streaming deals with at least one of those high-powered artists: The Beatles (ever heard of ’em?). Should you switch to Apple Music? That depends on a lot of factors, but it would certainly help if they can secure these artists who’ve been kept from Spotify, or the digital realm completely.

Taylor Swift

Swift’s entire catalog was on Spotify for the first three years of the company’s existence, but she made a public decision last year to remove all her albums (it should be noted that her albums are all exclusively available on Tidal). Essentially, she argued that there wasn’t enough money coming in from Spotify to justify keeping her music available. The service tried to get her back, and they came off a bit creepy in the process. Luckily for prospective Apple Music lovers, it appears that Swift has already agreed to a deal that’ll place her music on the service.

Dr. Dre

Okay, we’re cheating a bit here. To be clear, Dr. Dre’s 2001 is on Spotify, but his genre-defining solo debut The Chronic is not. It’s not on iTunes, either, and it wasn’t even available on Dre’s on Beats Music (eventually purchased by Apple for the sake of creating Apple Music). If Dre won’t even license his classic to his own service, it’s unlikely you’ll be able to hear it on Apple Music. The aggravating factor here is that The Chronic was on Spotify, as well as iTunes, but was removed from both, likely due to legal disputes. It’s not all bad; you can still hear “Forgot About Dre” on Spotify, but the lack of his best album is a major absence. One can only wonder if Detox will be included on the site if and when it finally comes out.

Thom Yorke / Radiohead

The Radiohead frontman has been one of Spotify’s most vocal critics, calling the streaming service “the last desperate fart of a dying corpse.” While almost all of that band’s albums are on the service (only the self-distributed In Rainbows is missing), his solo albums — as well as the albums from his side project, Atoms for Peace — are nowhere to be found. They’re available on iTunes, however, making them a good bet for Apple Music.

De La Soul

The legendary Long Island hip-hop group has been absent from streaming services and iTunes due to a mixture of label disputes and difficulty gaining clearance for certain samples. De La Soul thought of a clever solution to the problem, however: To celebrate the 25th anniversary of their debut album last year, 3 Feet High and Rising, they made all of their music available for free on their website for a 25-hour period. It was a nice gesture, but as someone who missed out on the promotion, me myself and I are hoping they’ll be on streaming services sooner than later. I’m not holding my breath, though.

Def Leppard

This is kind of a tricky one. Def Leppard’s music — or at least some of it — is available on Spotify and iTunes, just not in the ideal form. Their only proper studio album on the service is 1996’s Slang, which was not one of their most popular albums, critically or commercially. Classic singles like “Photograph” and “Pour Some Sugar On Me” do appear, but only in re-recorded form. Due to a dispute with their label over royalties, Def Leppard’s classic albums like Pyromania and Hysteria remain unavailable. This one isn’t looking good for Apple Music, either.

Garth Brooks

The country superstar has yet to put his music on Spotify or iTunes, and you may have noticed that his videos are absent from YouTube, as well. Brooks has an explanation for that: He thinks YouTube is the devil. He also applauded Taylor Swift’s decision not to boycott Spotify:

“YouTube; oh my god,” Brooks began. “They claim they pay people, [but] they’re not paying anything, either. People get millions and millions and millions and millions of views, and they don’t get squat. Trust me. Songwriters are hurting. So, I applaud Miss Taylor and I applaud everyone for standing up for the songwriters, because without them, music is nothing.”

He has started a streaming service called Ghost Tunes, which is basically the country equivalent of Tidal that absolutely no one asked for.

Bob Seger

Seger’s latest album Ride Out does appear on iTunes, but classic albums like Night Moves and Stranger in Town are absent from Spotify. In an interview with Rolling Stone last October, he chalked up his absence from the streaming service to an issue with his manager and his label, Capitol Records. The more revealing part of that interview, however, was that Seger doesn’t use Twitter or Facebook, and he doesn’t have an email address. He is 70, so it’s not that shocking. Still, it looks bleak for Apple Music.

AC/DC

AC/DC’s music is unavailable on any streaming service, and that seems unlikely to change any time soon. In a 2011 interview on That Metal Show, Brian Johnson cited the band’s refusal to appear on iTunes as an example of them going their own way (they eventually relented and joined iTunes in 2012). They don’t seem to be hurting too much without streaming; their latest album Rock or Bust sold 172,000 copies in its first week. But, given that they’re on iTunes and eventually ceded ground after a long fight, it’s possible that they’ll be on Apple Music eventually.

Tool

Tool singer Maynard James Keenan is so old school, his band’s discography isn’t even in the iTunes store. As a matter of fact, he won’t even let his record label create a greatest hits album, because he’s that dedicated to the sanctity of the album format. Don’t expect to find them on any streaming service anytime in the near future.

The Black Keys

Like Dr. Dre, they do have albums on Spotify, but you won’t find their last two — 2011’s El Camino and 2014’s Turn Blue, arguably their two most popular albums — on the service. Because The Black Keys do have some streaming presence, this isn’t a matter of sample clearance, and all of their albums are on iTunes, it seems likely that they’ll put those two albums on Apple Music eventually.