"[The figured bass accompaniment] blurs the independence both of the three contrapuntal voices which it theoretically contains and of the chordal or homophonic harmony which it supposedly illustrates. It breaks down the isolation of the voices by integrating them into one line, and of the chords by integrating them into a continuous movement. Linear form is essentially the isolation of the elements of music, and the history of music, until our day, may be seen as a gradual breakdown of all the various isolating forces of the art--contrapuntal independence of voices, homophonic progression, closed and framed forms, and diatonic clarity.
The attack upon the tendency to isolate comes paradoxically from within by means of the isolating forces themselves--just as, in painting, Impressionism went beyond Delacroix in its attempt to avoid isolating the larger forms, and yet its method was a doctrinaire isolation and equalization of each brush stroke. In music, the classical style attacked the horizontal independence of the voices and the vertical independence of the harmony by isolating the phrase and articulating the structure. Late eighteenth-century phrasing is emphaticallyperiodic, and comes in clearly defined groups of three, four, or five measures, generally four. Imposing this new periodic system upon the musical flow and blurring the inner progression of that flow by the new accompaniment figures meant that the linear sense of the classical style was transferred to a higher level, and had to be perceived as the continuity of the whole work, and not as the linear continuity of the individual elements.
The vehicle of the new style was a texture called the sonata."
Charles Rosen
The Classical Style: Haydn, Mozart, Beethoven