Harry Barris was an American popular singer and songwriter. He was one of the earliest singers to use "scat singing" in recordings. Barris, one of Paul Whiteman's Rhythm Boys, along with Bing Crosby and Al Rinker, scatted on several songs, including "Mississippi Mud," which Barris wrote in 1927.

Originating in vocal jazz, scat singing or scatting is vocal improvisation with wordless vocables, nonsense syllables or without words at all. In scat singing, the singer improvises melodies and rhythms using the voice solely as an instrument rather than a speaking medium. This is different from vocalese, which uses recognizable lyrics that are sung to pre-existing instrumental solos.