War is here again — the band, that is, with its first new studio album in 20 years. It was announced Tuesday that the genre-bending group — whose pop and R&B hits include Why Can't We Be Friends, Low Rider, The Cisco Kid, The World Is A Ghetto and Summer — is set to unveil Evolutionary, introducing 12 new tunes, on May 13. Guests on the album will range from Cheech & Chong (who appear on the first single, The L.A. Sunshine) to the University of Southern California Marching Band, also including Joe Walsh, Malik Yusef and the Tower of Power horns. Evolutionary will be released as a two-CD set and digitally, including a remastered edition of the band's Greatest Hits collection from 1976. This marks the first time that the hits album is available digitally or on CD. War is also poised to kick off a national tour March 20. The trek will include headlining dates with Cheech & Chong at Las Vegas' Hard Rock Hotel & Casino on May 16 and Los Angeles' Greek Theatre on May 24, A complete itinerary is at the band's site.