Celebrating 15 years of their sixth studio album.

Beastie Boys are toasting to yet another album anniversary. The legendary trio has issued a deluxe edition of their sixth studio album, To The Boroughs, featuring twelve previously unreleased bonus tracks.

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Add-ons to the 2004 album include a break-heavy Just Blaze remix of the lead single "Ch-Check It Out," along with edits of "Right Right Now Now," "Triple Trouble," and "An Open Letter to NYC." According to Billboard, a grip of the bonus tracks were only released as b-sides on CD singles.

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Earlier this year, the group's surviving members -- Ad-Rock and Mike D. -- hit the road in support of a new memoir, Beastie Boys Book, which was adapted into a Broadway production by Spike Jonze and an audiobook featuring narration from Nas, Talib Kweli, and Public Enemy's Chuck D.

Hear the deluxe edition of Beastie Boys' To The 5 Boroughs below.