Joe Budden rose to prominence on the mixtape circuit thanks to a close relationship with DJ Clue and scored a deal with Def Jam in the post–50 Cent era—back when hot mixtapes were seen as a golden ticket to success. After dropping a Top 40 hit with his lead single "Pump It Up," his self-titled debut album didn't sell as well as expected. But there was a heartfelt sincerity to his music that few rappers had. While that didn't equate to huge sales, it did lead to a die hard fan base that grew discouraged when Def Jam shelved Budden's sophomore album, The Growth.

Angry at the world and abandoned by his label, Budden hit the booth to vent his frustrations and ended up making the best project of his career, one so acclaimed it even got a writeup in the New York Times. The original Mood Muzik was a best of compilation, but the sequel was essentially an all-new album that featured almost entirely original production.

The mixtape has diverse styles, too. Sure, there were plenty of all-out lyrical blasts like "Dumb Out" and "Get It Poppin," but there was also personal introspection on songs like "Are You In That Mood Yet" and "If I Die Tomorrow." It turned out that deep in the dungeons of rap—where his addictions, ambitions, and failures were laid bare—Budden's potential could be fully realized. He might have felt cast aside and relegated to the underground, but maybe he was better off there in a time when major labels didn't have the time/budget/inclination to develop his talent.

This mixtape changed the trajectory of Budden's career. Who knows? Without it he might have been a forgotten artist, just one of rap's many one-hit wonders. Instead, Mood Muzik 2 fueled his career: He released several more volumes in the series, became an underground favorite, and eventually hooked up with Slaughterhouse and landed a No. 1 album last year. Are you in that mood yet? —Insanul Ahmed