The Progressive Four was one of the finest vocal quartets to come out of Washington in the late 1940s. Their reputation endured long after their radio broadcasts faded into the ether, and their 78rpm records became obsolete and hard to find. Group members included lead tenors Harmon Bethea and Lindsay Wilson as well as Hartwell Mouton, Wilburt Griffin, and Oliver Armstead, along with integral guitarist Thomas Singleterry. The group was especially adept at switching harmony parts amongst the members, a technique that caused their listeners to focus more intently on their performances.

Although a spiritual group originally, The Progressive Four was tasked with recording secular material by Mrs. Lillian Claiborne, co-founder of DC Records. Lead singer Harmon Bethea recalled: "Mrs. Claiborne made us sing all them old songs. Oh yeah! She managed us right from the beginning." Bethea was referring to pop songs such as "Saint Louis Blues," "Darling Nellie Gray," and "Basin Street Blues", which even by 1940s standards were beginning to sound dated. The group delivered them in a style known as “vocal jive”, which owed much to the earlier recordings of The Ink Spots, The Cats and The Fiddle. The Progressive Four took a peppy and improvisational approach to the material, and this mirrored their approach to spiritual songs. They sang those tunes in a Gospel Jubilee style, which was a nod to spiritual groups like The Golden Gate Quartet and The Silver Echo Quartet among many others.

Starting in the 1930s, the African-American gospel community grew increasingly hostile to the notion of religious performers also working in the pop or blues field. When Mrs. Claiborne had the group record pop music and appear on the radio with pop oriented-DJs, some members insisted that the group return to its spiritual roots. Signaling that change, a gospel disc which had already been released as a record by The Progressive Four was re-released in December 1948 under the name, The Corinthian Singers.

Harmon Bethea left to join a new group called The Cap-Tans, and the renamed group faded after a couple of more releases on Savoy Records which were drawn from DC Records' masters. While the Washington group may have been linked through John/Johnny Allen to the Atlanta-based gospel group which recorded for Columbia Records in 1930, there was no overlap in personnel, style, or repertoire by the time the Washington group recorded for DC Records in 1947. In total, The Progressive Four recorded some 10 discs (20 songs) between 1947 and 1948.