At least Stevie Nicks knows all the things she is. During a 90 minute set last night in the Polaris Amphitheater, which included tunes from the performer's solo career and her years with Fleetwood Mac, she displayed Nicks the rock star, Nicks the naive songwriter and Nicks the disco queen. During the "Acoustic-electric-acoustic" portion of the show, the singer introduced three songs about "moving to Hollywood and trying to make it as a rock star." She sang a trio of overwrought songs obviously the work of a youngster. Earlier in the set, though she was both a rocker and a star. Enchanted, which provides the title for the artist's new three-CD retrospective, proved she could rock hard. But her most popular work has focused more on her eccentric personality and confessional songs. The former was reflected both in the lovely stage set and her Victorian fashion sense. Unlike the musty incarnations of the past, her clothes, and the set, were more Liberace and less Miss Havisham. Every time she did her trademark spins, the crowd nearly shrieked. Songs such as Gold Dust Woman and Landslide were obviously more than mere pop songs in the eyes of Nicks' feverish fans. They express a tragic, if rather contrived romantic quality which strikes a chord. Suprisingly, so have the singer's dalliances with dance music. With Stand Back, and its ferocious beat, disco diva Nicks brought the house down.