Music historian Timothy Wise writes that it was the mass media of the time; radio, phonograph, and film, that spread the romantic myth of the cowboy and "popular music was integral to the mass mediation of the idea and of the representation of the cowboy, and yodeling was one of its primary signifiers." The transformation of Rogers' blue yodel to the cowboy yodel involved a change in both rhythm and a move away from Southern blues-type lyrics. Some yodels contained more of the Alpine type of yodel as well. Roy Rogers, singing with the Sons of the Pioneers in 1934, sings to a "sweet Tyrolean maid" in "A Swiss Yodel".