The soul patch (also known as a mouche) is a small patch of facial hair just below the lower lip and above the chin. It came to prominence in the 1950s and 1960s, when it was a style of facial hair common among African-American men, most notably jazzmen. It became popular with beatniks, artists, and those who frequented the jazz scene and moved in literary and artistic circles. Jazz trumpeters in particular preferred the goatee for the comfort it provided when using a trumpet mouthpiece.
Frank Zappa claimed his was called an Imperial in honor of Little Anthony. The Imperial actually started with Napoleon III. Zappa was right to call it an Imperial, but it was named after Napoleon III.