Traditional Chinese Music "Ambush"

I listened to the traditional chinese song "ambush from all sides" (found here: http://www.youtube.com/watch?v=JtrthXXmKgA&feature=related ) and decided to compare it to western music.

It is played on a traditional instrument called a pipa with strings and frets similar to a guitar, though tuned quite differently.

The song is, obviously, not bsed on any western scale.  It also appears to have no meter, which sets it clearly apart from western music.  Virstually no western music after the medieval period (ended in  1450 AD) does not have a meter. 
The song also had no steady tempo, which brings to mind the nocturnes of the romantic period, though I would venture to guess that in "ambush" the tempo change is set, rather than being improvised as in an character piece like a nocturne.
The music is also used to tell a story, which is another element similar to romantic western music.
The dynamic varied widely, between piano and forte, most likely for dramatic reasons.
The melodic contour was oscillating.  there was no particular tendency to move in a given direction, an the melodic lines were long and varied.
the melodic range was relatively narrow.  perhaps an octave and a half, an obvious consequence of using a single instrument.
the instrument was played as melody, though some chords were used.  frequently these chords were issonant for dramatic reasons.
The texture was, of course, monophonic.
the music did not seem to have any kind of structured, repeating form, though it did have a tendency to cycle regularly between calm melodic sections and dissonant, aggressive, fast paced sections.

Music - Yin1yue4
instrument - yue4qi4
melody - diao4
concert - yin1yue4hui4