Music -- National or Universal?

A question that has been on my mind for a while now, but I've not known how to approach, surrounds the question of "national" music.  I believe that it existed, and still exists.  But, what of those composers who strive to eliminate boundaries of nationalism and create not "world music" but a pan-world music?

In my readings this week, I came across a quote from Gluck, who in 1773 wished that his music “would appeal to all peoples” and “wipe out the ridiculous differences in national music.” (Marshall, Robert L.  "The Eighteenth-Century as a Music-Historical Epoch: A Different Argument for the Proposition." College Music Symposium 27(1987), 201).  This made me think of Henry Cowell, whose music was seen by some as moving toward a Neo-Primativism... driven by a need "to draw on those materials common to the music of all the peoples of the world, [in order] to build a new music particularly related to our own century."  (in Nicholls, David (ed.).  The Whole World of Music: A Henry Cowell Symposium.  Amsterdam: Horwood Academic Publishers, 1997.)

Here, we have two composers, who 160 years apart are consciously making an effort to create a sort of trans-ethnic music.  Granted, for Cowell, trans-ethnic is a far wider concept than for Gluck, but I would like to think that the background is the same, in trying to create a sort of universal music.  We have Cowell's own words that this was his goal.  Of The United Quartet, Cowell writes: This "is an attempt toward a more universal musical style." (in Taylor, Timothy D.  Beyond Exoticism.  Durham, NC: Duke University Press, 2007.)

Taylor offers some more insights on a new age, in which "we are germic embryonic seed of future majesties of growth" (quoting John Varian, ibid.).  So, how can I merge this deep-seated and important-to-me belief that "The earth is but one country and mankind its citizens" (to take the words from the Baha'i Writings) with the music that has become my passion to study, understand, and hope to lead others to understand as well?  This is my quest!