65 This concept of horizontal harmony corresponds also to one of the earliest meanings of harmony as a term and the associated theoretical framework in the Ancient Greek tradition. See: Andrew Barker, pp. 4,5. R.P.; Winnington-Ingram, p. 10.; Mariana Buleva, p. 541, 568, 599-605. It could be seen as pertinent also to the Western-European tradition at least until 6-th century, when a dichotomy of monodic harmony: ‘harmonia simplex’ and polyphonic harmony: ‘harmonia multiplex’ was theoretically formulated (Mariana Buleva, p.575).