Apple Music debuts Tuesday, about three weeks after the tech giant announced its new streaming music service in grand fashion.
The service promises on-demand access to 30 million songs, serving as Apple's answer to similar outlets like Spotify and Rdio. But not every musician will be a part of the worldwide listening party.
Taylor Swift famously threatened to keep her catalog off of Apple Music until the company agreed to pay artists royalty fees during an initial three-month free trial period for users. Popular acts like AC/DC, Led Zeppelin and the Beatles kept their music out of the iTunes store until agreeing to deals with Apple in recent years.
So who likely won't be found streaming when Apple Music launches? Here are four notable musicians that have either limited the availability of their music through iTunes, or have barred it completely.
Garth Brooks
While plenty of artists have publicly gone on record against online single-track music sales, Brooks has gone all the way and started his own music download company. Fans won't find a single one of his tracks on iTunes but can download his whole canon via Ghost Tunes, in the form of entire albums.
Bob Seger
In 2011, Seger ended his long-standing iTunes holdout ... sort of. The Detroit icon has ceded a pair of live albums, two compilations and his 2014 release to be sold through the iTunes store. Listeners who want to stream "Stranger in Town" or one of Seger's other classic albums in its entirety will likely be disappointed.
Def Leppard
The British rockers have been at odds with their former record label for years over digital sales rights, leading to the band not appearing on iTunes. Despite being one of the best-selling acts of the last 30 years, fans can probably expect to miss them when Apple Music unveils.
Tool
Of all the bands to keep its music away from digital streaming services, Tool has arguably taken the most hard-line approach. None of the band's catalog is available through any of the major streaming outlets, including iTunes. It's unlikely listeners will find Tool when scanning through Apple Music's library.
Apple Music launches for iPhone users with the release of iOS 8.4 at 11 a.m. Eastern, according to MacRumors. The service will launch for Android users this fall.
Clint Davis is a writer for the E.W. Scripps National Desk. Follow him on Twitter @MrClintDavis.
