By Chip Deffaa
Updated June 05, 1998 at 04:00 AM EDT

Few Atlantic jazz albums were more valuable than the six made between 1955 and 1962, documenting traditional, ensemble-oriented New Orleans jazz. The irreplaceable key players on The Atlantic New Orleans Jazz Sessions (gathered here by Mosaic on four CDs, with five previously unreleased tracks) are all dead now. Whether joyous or mournful, Percy and Willie Humphrey, Billie and De De Pierce, George Lewis, et al. opened their hearts. It’s impossible not to respond. A-