The growth of a musical structure where harmony represents an initial externalisation of the structure as implicit in melody is therefore part and parcel of a fundamental change in the overall social-intellectual structure. This chapter focuses on the musical coding of ideologies that both the pentatonically generated modality of plainchant and the subsequently developed language of tonality are mutually exclusive systems derived from the harmonic series; and that post-Renaissance society developed tonality as an integral facet of its own new ideology. Since biological characteristics are species-specific they can be assumed to be constant or neutral as far as the overwhelmingly social meaning of any particular music is concerned. Initially, therefore, some tentative suggestions will be made about the relationship of music and society in pre-literate cultures. Finally, in discussing the musical encoding and articulation of social meaning, some comparative remarks may be made concerning 'form' in pre-literate music and tonality.