This is a study of yodelling as a musical and cultural signifier. A definition of yodelling and a typology useful for the description of the various yodel phenomena heard in English-language popular music are proposed. Yodelling is then considered in a chronological sequence, beginning with abstract yodel signs in European instrumental classical music where these tended to signify pastoralism, idealism, and other ideas relating to romantic conceptions of the self. A discussion of yodelling in light classical and popular music through the nineteenth century follows. The differing ideologies associated with "art" music and "popular" music are discernible in attitudes toward the yodel during this time. The Americanisation of yodelling in terms of both its musical-formal manifestations and the ideas it articulated through these are discussed before considering yodelling's role in both the hillbilly and the cowboy genres. The emphasis throughout is upon the semiotic aspects of yodelling which I characterise as the difference between the" rough" and the" smooth". The yodel seems always to be associated with what is rough: peasants, shepherds, hobos, and hillbillies. This distinction between rough and smooth has a correlative in the very creation of the sound in the sense that the production of yodelling is a rejection of the orthodox classical singing styles with their cultivation of the "smooth" transition between vocal registers. The result for the yodel has been its thorough ironisation over the middle years of the twentieth century, as an emerging cool aesthetic could no longer countenance it.