Certain acquired tastes are worth the effort: caviar; single-malt Scotch; Sheila Jordan. Like her friend and sometime collaborator Mark Murphy, Jordan is that anomaly peculiar to the upper echelons of American jazz-an artist too superbly innovative to attract a mainstream audience. As an improviser she knows no equal, stretching her small voice to incredible limits. It was evident four decades ago on the landmark Portrait of Sheila (Blue Note)-an album so boldly imaginative, so distinctly outre, that no label would touch her for another dozen years. It's just as evident throughout Little Song (HighNote), a bracing new collection of blues and standards that derives its seemingly ironic title from the nickname bestowed on Jordan by her Cherokee grandfather. Bracketed by improvised Native American chants, Little Song wanders freely from the awed reverence of "Autumn in New York" and velvety desire of "On a Slow Boat to China" to an agitated "Hello Young Lovers" that drips with self-deprecating humor. Along the way, Jordan injects "Something's Gotta Give" with sinful determination, ignites the smoldering edges of "The Touch of Your Lips" and peels back the delicate layers of "When I Grow Too Old to Dream" with heartbreaking tenderness. It is, though, a newer composition-bassist David Finck's cunning "The Way He Captured Me" (sort of a softer, more cerebral "You Can Have Him")-that impresses most with its evocative blend of trumped-up enthusiasm and muted envy. Throughout Little Song, Jordan proves conclusively that she is, at age 74, still in her prime.