There are two fundamental historic attitudes toward the arts: the urge to revive the 'classical' however one may envision it, and the contrary urge to strike out in new directions. These two urges seem to be present in all times and eras. Here, for example, is a quote that demonstrates the former urge:
“I, too, used to like modern buildings, but when I began to appreciate classical ones, I came to be disgusted with the former.” The Italian architect and sculptor Antonio Filarete, writing in the 1460s and referring to Gothic buildings.
And here is a quote that shows the latter urge:
In 1558 the Italian music theorist Gioseffo Zarlino published his Le istitutioni harmoniche in which he commented "At present it is hardly possible to find an instance of fugal writing that has not been used a thousand million times by other composers."
At any given moment one can bemoan that we are stuck in a rut and just regurgitating what has been done before and simply must find new approaches. Or one can bemoan that we are sinking into decadence and barbarism and must rediscover the classical ideals and values. The Renaissance, ironically enough, in an attempt to revive classical ideals, instead managed to start Western culture in entirely new directions. Attempting to revive the Greek practice of musical accompaniment to tragedies, they invented opera.
I think we are at a potentially very interesting and possibly fruitful moment in the history of Western music. After a century of constant innovation and breaking with tradition, I think now is the time to consolidate. This is not at all the same as being reactionary. One can never return to a previous era and every time you attempt to revive something, you probably end up inventing something new, just as many attempts to invent something new end up as tiresome repetitions of something that came before.
But what an incredible storehouse of styles, idioms and techniques the 20th century has left us! There is so much there that can be explored and rediscovered. As a very modest example, when I set out to write a song on a poem by the 8th century Chinese poet Li Po, one line in the poem made me choose a technique often used by John Cage: the preparation of one string of the guitar so as to make a bell-like sound. The result is a piece with an unusual flavor:
Another example might be this piece by Osvaldo Golijov, titled Tenebrae which is a reinterpretation of music by François Couperin:
There are so many possibilities. I feel that what is important is reviving aesthetics rather than technique as a guide. So much of the last century was a frantic search for the new, regardless of whether it was good or bad, that now it is time to sort it all out--in individual ways, of course. Time to re-examine styles and ideas of the past, seek out interesting juxtapositions and relearn the aesthetics of music.
Here is another example: a piece for violin and piano titled Aria by Kevin Puts that combines a violin line that tends to the romantic with a minimal piano accompaniment. The result is neither romantic nor modern but something else. It is that aesthetic "something else" that is interesting, I think.