Social theorists have long been aware that participation in the ownership and control of material or intellectual property creates a different relation to the world and a different interest from the non-participation of people who can only sell their labour power. Clearly, the field of twentieth-century music is both vast and extremely diverse. This diversity can itself be seen as relating to the high level of social stratification in our society. Church music and the manufacturing of commercially popular songs have mediated between the music of the elite and that of the folk. The gestalt of sounds which constitute an utterance is the 'music' of speech, and the attack, the rhythms, the intonation of the melody is absolutely meaningful. The relationships of social life — the class structure — and attitudes towards them are articulated as much by musical as by verbal forms. Pitch inflexion is also to be found in the practice of Western folk and 'popular' music.