Sun Ra's inquisitiveness ranges all over the solar system, but it begins with the blues and makes use of skills acquired from decades of solid experience as a composer/arranger (beginning with his 1940s apprenticeship with Fletcher Henderson). The seriousness of Ra's intentions becomes dear when you see the discipline he imposes on his fantastic big band: ranging from butt-shaking drum beats (Ra's vision of "outer space" sounds interestingly African) to swinging choral chants to spacy atonal noise to the funkiest of funky swing, the Arkestra becomes a unique interplanetary civilization unto itself. Meanwhile, Ra's instinctive flair for mythic spectacle (visually elaborate shows full of dancing and flashy costumery, in which ancient Egypt meets 1950s science fiction) is not only lots of fun but also an elaborate metaphor for some of the most positive human urges: the drive to seek, to explore, to expand in knowledge and in spirit. This, after all, is what music and life are really all about. Sunday, FitzGerald's, 6615 Roosevelt, Berwyn; 788-2118.