In our analysis of the theme, we begin with complex themes which contain a plurality of data such as a sequence of musical notes which form a melody. Later, ¹ we will consider the organizational structure exhibited by "simple" cases, for example, a musical note sounding for some time, in which the theme consists of a single datum emerging from a background. In order to present our analyses in their historical context, we will first examine, some theories which account for the phenomena under discussion on the basis of the conception of sense-data as primary contents of consciousness.