I've got good news and bad news. First, the bad news. If you get the chance to avoid seeing BLACK OAK ARKANSAS at the Orpheum Theater, take it. This has to be one of the worst groups to hobble down the pike in a long, long while. Jim Mangrum's performance as a lead singer comes off like a pitiful imitation of Mick Jagger doing a deliberately bad rendition of Grand Funk Railroad's greatest hits.

But there is good news in abundance:

BONNIE RAITT AND JACKSON BROWNE. Bonnie Raitt dropped out of Radcliffe for records and roadtrips, and has become one of the finest and most versatile rock and blues singers around. She handles six-string, National Steel, and bottleneck guitars with equal grace. She can take even flimsy material and transform it into rousing, gutsy blues.

Jackson Browne's songs are bouncy, and if you listen to them closely, dull. But he is at least energetic and probably will not detract from what should be a first-Raitt concert.

DOC WATSON AND SON. There's no better flatpicker in the country than Doc Watson, and his son Merle becomes better on guitar and banjo all the time. The Watsons' past Sanders Theatre performances have been sell-out, standing ovation-type triumphs. Given their skill and the range of their material--bluegrass, blues, traditional folk, and popular folk--this concert is likely to remain true to their tradition.

MARIA MULDAUR. Muldaur has emerged from a career of background harmonizing, singing for Jim Kweskin, and making only promising records with her husband Geoff to become a highly original solo interpreter and exciting stylist in her own right. Passim should provide the perfect arena for her talents; when Passim was the Club 47, Muldaur was reportedly responsible for some of its finest moments.

BONNIE RAITT AND JACKSON BROWNE. Fri. Oct. 5 at the Aquarius Theatre, 8 p.m., $4-$6.

DOC WATSON AND SON, LEON REDBONE. Sun. Oct. 7 at Sanders Theatre, 7:30 p.m., $3.50.

MARIA MULDAUR AND LEON REDBONE. Thurs. Oct. 4 through Sat. Oct. 6 at the Passim Coffeehouse, 492-7679 for information.