Just when the big popularity of the "disco sound" s about to make us forget where the term "funky" comes from, a performer like bluesman Louisiana Red comes to town to give us some of the real thing. Red played along with harmonica man Sugar Blue at Herb Cohen's Raven Gallery in Southfield for six nights last week, delighting ordinary music fans just as much as the flippcd-out blues freaks in attendance. Louisiana Red (whose current album, Sweet Blood Cali, s on Blue Labor Records) s one of those ' classic country blues artists who came up from the delta to find work n the cities, bringing his guitar, his tales of hard luck and hard times, and the roots of our music with him. Above all else, he is a communicator- deal ing as much with emotions as he does with notes and chords. His "Louisiana Red Boogie" is a romping, stomping, lose-yourjblues blues, while tunes Mke"ltWill Be Hard To Miss You" are life's agonies played on a guitar. Red appears as usual with the young, agile, energetic Sugar Blue on mouth harp (harmonica). Sugar's been out breaking new ground with jazz vocalist Leon Thomas, and was last seen with him at Baker's Keyboard Lounge.