A rap album that holds new-school innovation and old-school basics in perfect balance; a double-album colossus with a minimum of filler; a veteran group’s affirmation that after 20 years in the business, they are better than ever. Without question, Underground Kingz is a rare accomplishment on multiple levels. Atlanta’s own dynamic duo appears here on “Int’l Players Anthem (I Choose You)” a beam of endless radiance that brings together the South’s top minds over a timeless Willie Hutch sample. Yet the album only begins there. Following a seven-year absence from recording and Pimp C’s four-year incarceration, Underground Kingz is designed as a comeback album on the highest order — both a reaffirmation of a signature sound that helped lay the foundation for Southern rap music, and an authentication that these 20-year veterans can compete with the best that the younger generation has to offer. “Chrome Plated Woman,” “Quit Hatin’ the South,” “How Long Can It Last,” and “Shattered Dreams” are molasses-and-gravy-coated Pimp C productions that stand next to anything from Ridin’ Dirty or Super Tight, while “Grind Hard” and “Take the Hood Back” prove that the group can ride as hard and heavy as the current crop. The guest list (everyone from Too Short to Talib Kweli to Big Daddy Kane) reflects UGK cross-regional appeal, but the duo alone shines strongest. “The Game Belongs To Me” is definitive UGK: the lifetime partners, trading sneers and stories over syrup-thick soul music.