Breaking the pattern of their two previous releases, the group's 1969 studio LP, "String Fever" (often mis-titled as "Spring Fever"), focused on original material, producing tracks such as "Zambezi" and "Chocolate Candy". Aside from Evans' compositions, the album featured songs written by or with Hathaway and Upchurch. Grogan describes "String Fever" as, variously, "by far the best of the Soulful Strings albums" and "the group's masterpiece". Producer and DJ Kirk Degiorgio, in his role as an educator with the Red Bull Music Academy, similarly included "Zambezi" and "Chocolate Candy" on his playlist reflecting the best music from Evans' career. The group's final LP, "Play Gamble-Huff", consisted of cover versions of songs by Kenneth Gamble and Leon Huff. The album appeared in early 1971, by which point the Chess brothers had sold Chess Records and its subsidiaries to General Recorded Tape (GRT). In 1972, the GRT-owned Cadet label issued a compilation album by the group, a two-disc set titled "The Best of the Soulful Strings". Release information per Both Sides Now Publications' Cadet Records discography (albums) and Funky16Corners (singles); all chart peaks from US charts compiled by "Billboard" magazine.