 The most popular groups in the 1930s were male quartets or small groups such as The Golden Gate Quartet, who sang, usually unaccompanied, in jubilee style, mixing careful harmonies, melodious singing, playful syncopation and sophisticated arrangements to produce a fresh, experimental style far removed from the more somber hymn-singing.These groups also absorbed popular sounds from pop groups such as The Mills Brothers and produced songs that mixed conventional religious themes, humor and social and political commentary.They began to show more and more influence from gospel as they incorporated the new music into their repertoire.