Wagner as a Modern Composer

I think this is just going to be where I put things that I write. I've got a lot that isn't papers for school, but it just so happens that this next one is. I was only supposed to write a paragraph. I don't see how that's possible since this subject is easily debatable. I kept it at a page, though.

Twentieth century music, or modern music, is considered to have started in the year 1900. No other musical era is this exact. There is usually some overlap, which leads to some questioning about whether there is overlap between the romantic era and the modern era. Most books and articles on the subject of modern music do not include the last two decades of the 19th century as modern music, but they willingly acknowledge the influence of Wagner and Mahler on modern music.
It is clear in the romantic era that music is taking more liberties. A composition working itself through multiple keys is largely accepted. The strict sonata form is loosening, and compositions are becoming longer. By 1880, rather than modulating through many keys, pieces are highly chromatic and dissonant. There is still the desire to resolve the dissonance, but it is resolved in terms of the chromatic patterns that are set up.
The form of pieces by 1880 is so far loosened from the classical era, that it is hard to place names to the forms used. Instead of focusing on key sections, leitmotifs make up sections of the pieces. Combinations create different emotions and pictures.
Modern music is freer in regards to melody, harmony and structure. Music has reached this point by the time of Wagner. He is a model for what comes later in the modern era.