The ads for Ray Brown’s appearance call him the “world’s richest bass player”; if that’s true (and it may well be), no one would deserve it more. Brown still displays such remarkable control of his instrument–unflappable time, precision-tuned technique, and a tone solid enough to hang your hat on–that it’s hard to believe he’s a senior citizen (one month shy of 67). And he has played so well for so long that most of us take him for granted, easily overlooking both his place in jazz history and his present-day achievement. Brown made his first records in 1946, at the age of 19, with bebop legends Gillespie and Parker; then he took part in the creation of the Modern Jazz Quartet, accompanied (and married) Ella Fitzgerald, and anchored the fabled Oscar Peterson Trio of the 50s. Those associations made him, like Oscar Pettiford and Charles Mingus, one of the most influential bassists of the last 50 years–and the many hundreds of recordings to which he’s lent his sterling musicality over the last three decades didn’t hurt either. Brown’s trio boasts the versatile and underrated drummer Jeff Hamilton and pianist Benny Green, who has progressively mastered the prevailing piano styles of the 40s, 50s, and 60s. They stick to familiar idioms and an uncomplicated swing, and you won’t hear anybody do it better. Tuesday through next Sunday, September 5, Joe Segal’s Jazz Showcase, Blackstone Hotel, 636 S. Michigan;’ 427-4846.