The album, named one of Rolling Stone's 500 Greatest Albums of All Time, is not available on Spotify or Rhapsody and was not even part of Beats Music.
Its absence may have been due to legal disagreement over the digital rights to the album. In 2011 a judge ruled that WIDEawke Death Row Records could not sell the album digitally and granted Dre 100% of the proceeds of online sales.
Later Dre sued to recover money made on The Chronic between 2006 and 2009, which included $676,444 of mechanical royalties, $1.2 million of artist and producer royalties and nearly another $1.2 million in gross sale proceeds from unauthorized digital sales. Last year a judge denied Dre's attempt at royalty recovery because it was partly precluded by earlier rulings and otherwise barred by statute of limitations.
In addition to The Chronic, Apple Music will also stream the album 1989 from Taylor Swift which is not available on other streaming services.
Apple Music is set to launch tomorrow at 8AM PT.