This question is indeed very difficult to discuss. First you have music that covers a huge time frame containing many forms and styles of music. However, I am going to treat is as if I am comparing Bach, whose music used tonality, to those composers who moved from tonality to atonal(no tonal center) or 12 tone compostion. The question is "Does the moving of tonality to other tonalities stem from Bach's method of compositon?" 1. From reading about Bach's use of tonality in a different method than what was allowed in music composition at that time, Bach began to use a different method of using tonality in his vocal music. 2. He used a literary form called the allegory. 3. The allegory in literature conveys its message of symbolic figures, actions, or symbolic representaion. 4. Bach attempted to used tonality to depict allegory in Biblical texts. 5. I am not too familiar with the use of the methods used in literature, but I am sure Bach used those symbols I talked about on #3. 6. The serialists use a musical method, instead of a symbolic one, in the use of tonality. 7. The 12 tone scale is used with it's own rules, as using all the 12 tones before coming back to the first tone used. It is a more mathematical system. 8. Is it an extension of Bach? All I can say is that classical music is all related. The rules of composition always remain. Yes, changes occur to fit the style, but music remains as music. 9. You can compare this to an automobile. Yes, someone invented the automobile. It has gone through many changes throughout the years. It will always continue to change because the world changes, but it still remains a car.