THERE ARE three kinds of people in the world: those who've never heard of Etta Jones, those who are forever confusing her with Etta James, and those who know her as one of the great unsung vocalists in jazz and R&B.

Anyone who falls into the latter category pretty much knows what to expect from "Sugar," Jones's latest collaboration with veteran tenor saxman Houston Person. It's another soulful, sensuous and sassy set of ballads and blues -- old-fashioned, uncluttered and no doubt likely to win a mere fraction of the attention it deserves.

As usual, Jones and Person make for a wonderfully expressive combination, beginning with the Alberta Hunter hit "Sugar." Spry, sly and sexy, Jones's voice has an after-hours earthiness that's custom-made for the lyric, and she later displays a similar affinity for "He's Funny That Way" and "Blow Top Blues." She's not alone, however, in drawing the listener into the song. Person's hefty tone and unruffled phrasing adds weight to the performances, as does his incendiary bursts, and the small combo settings are occasionally dotted with insinuating solos from guitarist Randy Johnston. This time around, though, there is an unexpected twist: Rounding out the record are a couple of sentimental duets with singers Earl Coleman and Della Griffin.

ETTA JONES AND HOUSTON PERSON -- "Sugar" (Muse). Appearing through Saturday at Trumpets.