While it showed the growing divide between André 3000 and Big Boi (and presaged their long hiatus), OutKast's fifth studio effort was a highwater mark for the group all the same. It was essentially two solo albums: André's The Love Below and Big Boi's Speakerboxx, packaged as a double record. Two of OutKast's most enduring and innovative tunes are here: Big Boi's "The Way You Move" (a '70s funk throwback in the style of Cameo and Chic) and "Hey Ya" (André 3000's kaleidoscopic, decade-defining rave-up). Selling more than 10 million copies, Speakerboxx/The Love Below was OutKast's least classically hip-hop album to date; it was an ambitious amalgam of funk, soul, R&B, disco, and rock (try classifying the snarky kiss-off "Roses"). In mashing up so many sounds so successfully, the album closed the door on hip-hop's boom-bap '90s period, ushering in an era of sonic cross-pollination between hip-hop and pop that persisted into the next decade. Awarded a GRAMMY® for Album of the Year in 2004, this was one of OutKast's (and pop music's) finest hours.