When historians look back on the evolution of rap as a genre, it's likely that the late '90s will be remembered as a golden age of progressive hip hop. Just as the late '80s saw the growth and development of important, influential artists (Beastie Boys, Eric B. & Rakim, EPMD, De La Soul, Public Enemy), the past year and a half has seen a slew of landmark albums being released by a new breed of hip-hop visionaries from Lauryn Hill to The Coup to Outkast to The Roots. It's also seen a return to form from a slew of the late 1980s' finest, from Gang Starr to the Beastie Boys to Prince Paul, the brilliant, eccentric producer and DJ who helped create progressive hip hop with his work on De La Soul's 3 Feet High And Rising and De La Soul Is Dead. But while De La Soul has grown increasingly conventional, Paul has held his ground, creating new and challenging work first with RZA and Fruitkwan as part of The Gravediggaz and then on his first solo album, Psychoanalysis (What Is It?). But though Psychoanalysis was interesting and daring, it lacked one crucial element: memorable songs. In that respect, his wildly ambitious new record, Prince Among Thieves, represents a culmination of everything he's done over the course of a brilliant but messy career, combining the tuneful pop accessibility of his work with De La Soul and Stetsasonic with the darker, more personal music he's made since his departure from De La Soul. Operating as a sort of rap musical, Prince Among Thieves tells the story of a young rapper (Breeze) who needs to make a quick $1,000 to finish off a demo in time for an all-important meeting with RZA of The Wu-Tang Clan. With the assistance of his good friend and coworker (Sha), Breeze takes to hustling, which leads him on a dark journey during which he encounters everyone from an insane weapons dealer (Kool Keith) to a corrupt cop (Everlast) to a comical crackhead (Chris Rock). Of course, the album's elaborate framework wouldn't mean a thing if Paul didn't deliver the old-school goods: dynamic beats, on-point rhyming, and memorable lyrics. Luckily, he more than rises to the occasion, delivering the essentials with an ambitious vision that adds up to more than the sum of its parts. The album's two little-known stars make a particularly strong impression, more than holding their own against some of the biggest names in hip hop. For years, Prince Paul has maintained a relatively low profile, but Prince Among Thieves should help him earn the respect he so clearly deserves.