Not since the end of the Beatles and Lennon and McCartney's scathing recorded swipes at each other have we seen such public rock-star spatting as in the wake of the splintering of N.W.A. After this immortal bunch of gangsta-rap nogoodnicks (whose first album, Straight Outta Compton, put out-there rap on the map) saw the departure of its most distinctive voice and most thoughtful writer, Ice Cube, the remaining members, led by label owner Eazy-E, recorded a track that promised to "cut yo' head off and fuck you with a broomstick." Responded Ice Cube on Death Certificate, "Eazy-E will be hanging from a tree / ... Just a match and a little bit of gasoline / Light him up . . ." A year later the group's talented producer, Dr. Dre, split as well, a potentially crippling blow. (in a short career Dre had become one of the most successful producers in pop-music history.) In short order he turned on Eazy-E as well, nicely eviscerating him in the video for "Fuck With Dre Day," a major hit. Now Eazy-E has responded with a new record, whose title, It's on (Dr. Dre) 187um Killa, undoubtedly disguises some massive insult. Unfortunately, the unintelligibility of the album's title is on a par with its music, which, to go back to my original analogy, is a little like listening to an astonishingly foulmouthed Ringo and George dissing the departed John and Paul: even the documentary value is overwhelmed by the lousy artistry. Eazy as a solo act has a bunch of problems: his raps are crude even by N.W.A. standards; his voice, though he tries to disguise it with various studio treatments, is thin and reedy and the beats, without Dre around to help, are dullsville. One shudders to think what he has in store for unsuspecting concertgoers. Friday, 10 PM, Riviera Theatre, 4746 N. Racine; 275-6800.