Amazon.comWhen the Delmore Brothers moved to Memphis and to King records in the mid '40s, their sound took on bluesy, protorockabilly shadings, though their harmonies remained as complex and varied as any in country music. Alton and Rabon still retained a characteristic lilting and mirroring vocal style, with some yodeling and surging falsettos, but the playing of Merle Travis and blues harpist Wayne Raney drove them to the edges of hillbilly-boogie terrain. On these 18 songs from 1944 to 1949, the brothers sound aggressive and determined after the tumultuous 1930s: "Someday You'll Pay," "'Dis Train," and their two classic blues--"Brown's Ferry" and "Sand Mountain"--have the edginess that distinguishes this period, at once the high point and end point of their work together. --Roy Kasten