Ride in the whirlwind

Though it broke through to the mainstream with 2000’s “Stankonia,” OutKast has been pushing the creative envelope since its inception in the mid-’90s. With each new release, Atlanta rappers Andre 3000 and Big Boi have moved further away from categorization and conformity.

It’s this steady progression that makes this new, two-disc album such an artistic triumph. It’s not just that the collection stands so far above much of today’s contemporary hip-hop and R&B; but that it surpasses the high level of genre-defying craftsmanship that the duo has cultivated for nearly a decade.

OutKast’s 1994 debut, “Southernplayalisticadillacmuzik,” was pregnant with promise. Smothering tracks in smooth Curtis Mayfield-esque grooves filtered through a countrified version of Dr. Dre’s G-Funk sound, the group’s production troupe, Organized Noize, created a sound that marked the birth of the Dirty South -- a phrase identifying a gritty yet cool, streetwise yet classy Southern ethos.

With “ATLiens” in 1996 and “Aquemini” in 1998,” the duo moved forward on various levels, taking over the production reigns in the latter CD. The commercial blockbuster “Stankonia” introduced millions to crunk -- the bass-heavy, body-rocking, chant-driven music favored in the Dirty South.

In this album, which is due in stores Tuesday, we are taken further into the musical whirlwind that is OutKast, and in a way that it’s never been done before. Conceived as two separate solo albums, the sounds and themes vary greatly -- and always with pleasing results.

Big Boi’s “Speakerboxxx” pops with serious electro-funk: triple-time rhythms clocking in at more than 100 beats per minute; rabid rhyme schemes that brag, boast and decry social ills; and tweaked vocals that add a surreal touch to the experience.

On “Ghetto Musick,” he admonishes other rappers for the mostly stagnant state of the hip-hop these days.

On “The Love Below,” Andre’s commentary is more subtle. A work of aural theater, the album finds Andre donning multiple personalities -- including Cupid Valentino, the superfly patron of Valentine’s Day, and Ice Cold, a womanizing musician whose tribulations serve as the project’s narrative. Andre takes time to rap on only a handful of tracks, opting to sing and speak his mind elsewhere.

The music ranges from lounge jazz to Rick James-like funk to bombastic soul explosion that recall Ike & Tina Turner. There’s even a rendition of “My Favorite Things” set to drum ‘n’ bass music. On the romping “Hey Ya!” he asks partyers to “shake it like a Polaroid picture.”

Despite going their separate ways here, OutKast’s duo have made a cohesive statement that not only cries at the boundaries of rap music but vaults over them to a place where the music sounds like neon colors and the only rule is that you must free your mind. Your ears will follow.

-- Kris Ex