After-hours piano, boots-are-for-walking bass and heavy-on-the-off-beat drums burst from a darkened stage at the outset of the Charlin Jazz Society's "The Blues" concert at the Ethical Society Saturday night in a brief preamble to the entrance of Washington's premiere blues singer, Nap Turner. The West Virginia-born, longtime D.C. resident kept the 300-strong audience rocking in their seats for an hour as he expatiated in song on despair and loneliness, pleasure and joy, demanding women and slippery highways.

His deep, resonating voice employed stop time, supressed chuckles, moans from the gut and rim-shot sharp explosions as he moved from double entendre erotica to a prayer in blues clothing to the hip scat of bop. Charlie Hampton, on flute and tenor, alto and curved soprano saxophones, played congregation's response to Turner's preacher call and the rhythm support of the B.W. 3 (pianist Marc Cohen, bassist Tommy Cecil and drummer Hugh Walker clicked from the word go). It was a class act.

In stark contrast to the raw emotion and earthy humor of the first half was theveneer of respectability lent by former Lucky Millinder vocalist Bullmoose Jackson to a succeeding program of pop standards of yesteryear. He charmed, whereas Turner aroused.