This set not only contains material released on the studio albums “On the Corner” (1982), “Get Up With It” (1974) and “Big Fun” (1974) but also 12 previously unreleased tracks, notably the brooding “Mr. Foster” and “Chieftain,” which melds Caribbean rhythms and Near Eastern colorings. There’s a total of more than two hours of new music among the 6 1/2 hours of music.