As a rapper, Mississippi's Big K.R.I.T. is pretty good but nothing amazing: With the empathetic warmth in his sticky drawl, he makes a convincing Southern everyman, and he has enough rhythmic dexterity to really stick to beats. On the new, free-for-download mixtape Return of 4Eva, he invests the cars-and-girls talk he's already been doing with a sort of conscious-rap sensibility; toward the back end of the tape, he leaves behind boasting to talk about poverty and racism and materialism, sometimes coming up with a truly evocative line. But he's also lost some of the snarl that made his delivery so great on tracks like last year's Curren$y/Wiz Khalifa collab "Glass House". He can get a bit clumsy when he tries to transform himself into some kind of loverman. And even in his strongest moments, he still sounds a whole lot like T.I. without much of T.I.'s effortless, charismatic confidence. He could still become an excellent rapper, but it hasn't happened yet.

As a producer, though, he's good enough that he could be half a Ying Yang Twin and his music would still be well worth the hard-drive real estate. On last year's free online album K.R.I.T Wuz Here, he marked his place in a lineage of organic, soul-sampling Southern rap producers that includes giants like Pimp C and Organized Noize, making hard-thudding personalized version of the tracks he must've heard growing up. On Return of 4Eva (still free, still online), he progresses even further, turning his sound into a sleepier, woozier flutter-- a comfortable bed for his voice to sink into. Refracted versions of guitar and organ sounds wind their way through oceans of bass, all building into a perfectly evocative, nostalgic sound. Every once in a while, he'll come with something harder, like the skeletal keyboard bloops of "My Sub" or the horn-and-organ thunder of "Sookie Now". But for the most part, he focuses on turning classic Southern rap sounds into comfort-food background music-- the sort of thing that sounds absolutely gorgeous in a car on a warm spring afternoon, when you're driving slow with the windows open. There's a reason that Return of 4Eva dropped just as the weather was getting warmer.

In a sense, Big K.R.I.T. is like a hip-hop version of a group of rock revivalists. The same way that, say, Band of Horses turns dusty Neil Young guitar epics into something simple and comforting, K.R.I.T. trades on our collective memory of mid-90s Southern rap and turns that into brilliant invitations to nostalgia. At the end of "Sookie Now", we hear a sample of Don Draper philosophizing in "Mad Men": "There is the rare occasion when the public can be engaged on a level beyond flash-- if they have a sentimental bond with the product." K.R.I.T. included that sample to draw attention to his younger rap peers; he's the type of old soul who still complains about "ringtone rappers" sometimes. But it could just as well describe the Pavlovian attachment some of us have to a beautifully looped-up soul sample. And Return of 4Eva is absolutely packed with cascading looped-up falsetto harmonies. Sometimes, it feels like a set of variations on the beat for OutKast & UGK's "Int'l Players Anthem (I Choose You)". And since "Int'l Players Anthem" is one of the greatest rap songs of the past 10 years, that's no complaint.

Return of 4Eva doesn't have too many guests, but most of the people who do show up are Southern rappers who peaked maybe seven years ago: Chamillionaire, David Banner, even Ludacris on a remix of last year's "Country Shit". All those guys sound reinvigorated; K.R.I.T.'s amber-hued production gives them a context that just works for them. And one of the real revelations here is K.R.I.T.'s own singing voice. Taking on a few hooks himself, he's got a thoughtful, bluesy coo that seems custom-built for his tracks. It's fun to imagine what might happen if K.R.I.T. teamed up with an honest-to-god great rapper for a full-length. He and Yelawolf have been teasing a mixtape together for a while, and that could be incredible. But for now, Return of 4Eva, all glowing warmth and lazy-afternoon drift, stands as one of the finest rap releases of 2011.