HOLLYWOOD (Variety) - Twenty-five years ago, a bill like this one would have been inconceivable. Merle Haggard, the one-time king of country, supported by an all-black gospel vocal group and a Dylan/Woody protege from Brooklyn -- ha! But in 2002, legendary and American-rootsy is a wide spectrum, and these three acts are compatible in that all uphold venerable traditions -- that, and most of their kudos come from somewhere besides the radio, which doesn't play them very much if at all. In the case of the headliner, country radio's almost total blackout on the man who had more hits in ...