In the biography "Brother Ray," R&B pioneer Ray Charles said he had no problem with performers adopting a style similar to his own. But he singled out British belter Joe Cocker, suggesting that the spastic singer slept with Charles' records. Well, I hate to break it to you, Joe, but your record collection's cheating on you. Blues pianist Adrian Duke echoes Brother Ray so hard, he probably needs to be walked to his piano stool. Duke's act might be derivative, but that doesn't detract from the power and emotion he brings to the stage. Duke, who recently performed for the Queen of England, closes Karneval, the weeklong music fest at Capital Ale's Downtown Music Hall, on Fat Tuesday, Feb. 5, at 7 p.m. $5. 643-2537.