<P> Current dictionary definitions, while attempting to give concise descriptions, often highlight the ambiguity of the term in modern use . Ambiguities tend to arise from either aesthetic considerations (for example the view that only pleasing concords may be harmonious) or from the point of view of musical texture (distinguishing between harmonic (simultaneously sounding pitches) and "contrapuntal" (successively sounding tones). In the words of Arnold Whittall: </P> <P> While the entire history of music theory appears to depend on just such a distinction between harmony and counterpoint, it is no less evident that developments in the nature of musical composition down the centuries have presumed the interdependence--at times amounting to integration, at other times a source of sustained tension--between the vertical and horizontal dimensions of musical space . </P> <P> The view that modern tonal harmony in Western music began in about 1600 is commonplace in music theory . This is usually accounted for by the replacement of horizontal (or contrapuntal) composition, common in the music of the Renaissance, with a new emphasis on the vertical element of composed music . Modern theorists, however, tend to see this as an unsatisfactory generalisation . According to Carl Dahlhaus: </P> <P> It was not that counterpoint was supplanted by harmony (Bach's tonal counterpoint is surely no less polyphonic than Palestrina's modal writing) but that an older type both of counterpoint and of vertical technique was succeeded by a newer type . And harmony comprises not only the ("vertical") structure of chords but also their ("horizontal") movement . Like music as a whole, harmony is a process . </P>

When did harmony first appear in western music