The Marx Brothers began as a musical group, during the days of vaudeville theater. They would make jokes, play funny characters, and pretend to get into fights when they performed. In time their got them more applause (and work) than their music, and they became a comedy group. Music stayed in their act, with the brothers performing in character, but their focus was on getting laughs. Makeup and costumes gave their characters their look. When the brothers were out of costume, they could blend into the audience.