I posted a pretty long-winded response, addressing his question but also proposing many of my own observations and hypotheses. It was a long enough response that I figured it warranted it's own blog entry. So without further ado, here it is:
I think one of the most fascinating areas of "musicology," if you could call it that, is the analysis of the present musical climate and the speculation of what's to come. The points you've brought up and the questions you've asked, while pertaining to percussion, also reflect some serious speculation about the future of the industry as a whole.
When I started grad school, I ranked "deficient" in every period of musicology--from the middle ages to 20th century. I'm actually pretty thankful about this, because the level of concentrated study I had to do in order to keep up really helped guide my own views and goals as a musician. I guess the one thing I was left with overall is that nothing in music changes without a reason. Without the significant changes to society, the economy, and most importantly, technology, music would not have evolved much at all. As I finish my last semester of musicology, I finally feel like everything is coming together to create a logical historical narrative--one from which I can use to speculate the next chapter.
I think, in a few decades from now, musicologists will begin to start placing the date in which "20th-century period music" ends and "21st-century period music" begins, and my best guess would be to place it somewhere between 1980 and 2010. At the ripe age of 24, it's not really easy for me to confidently define a musical period as ending before I was born, but the criteria that I'm using is the shift from the dominant compositional innovations pertaining to experimentalism and re-definition of music (through innovators like Schoenberg, Cage, Reich, Ives, and others who leveled the playing field on what music and art can be) to composers of music for mass media consumption--composers like John Williams, for example.
What happened in the period of time I offered was the explosion of communicative technology--in 1980, you sent letters, worried about long distance phone call charges, and listened to music in analog formats only. By 2010, internet speeds fast enough to video chat with someone in another country were commonplace, concerns about long distance charges were replaced by concerns over how much data your smartphone was eating, and music was immediately available all the time through YouTube, iTunes, and other streaming sources and online marketplaces. This is also responsible for the new preference for eclecticism we see in young listeners today--so many different styles of music are immediately available, having a playlist skip from hip-hop to bebop to dubstep isn't really that shocking anymore.
Because of the way media has permeated into our lives, through movies, television, video games, and other things, the music connected to this media plays an important social role as well. When my 17 year old sister hang out with her friends, I always notice how whatever they listen to depends on the group she's with. Just like how our movies and tv shows use music to establish an atmosphere, we do this with our everyday lives. With the wide variety of styles immediately available to us, this has never been easier.
So how does the success of a percussionist in contemporary music reflect this? In society today, once again responding to technology, there's an expectation of versatility and immediate convenience. We expect our phones to take pictures, we expect our video game systems to play movies, and we expect our computers to do everything. This level of convenience is beginning to become expected, and is why digitally-produced music is slowly replacing live recorded music in our media. That all being said, live performances still play an important role in society, and composers and producers alike still rely on performers.
Percussionists, by default, are extremely versatile. Nowadays, a percussionist has to be proficient at mallet instruments, drumming, timpani playing, and anything else thrown our way. The expectation of playing anything thrown at us--whether actually percussive or not--has been integrated into our path of study. We are, in many ways, the "smartphone" of an instrumental ensemble. I think composers trust percussionists more, in this regard, to be able to keep up with the rapidly rising expectation of convenience and immediacy through this versatility. So yes, we serve as strictly "color and texture" less frequently now, because composers are realizing the advantages to working with musicians who can be color, texture, melody, harmony, and groove--and switch between roles quickly.
I think the other circumstance that sets us apart is that our tradition is simply much younger than other instruments. Violins have a long timeline, spanning hundreds of years, in which their instrument has developed, and in which their greatest repertoire has been written. Percussion, however, has a much shorter timeline, and most of our important repertoire was written in the last 100 years. Percussionists don't have as much trouble "adjusting" to contemporary music because we're already used to playing it. For this reason, we're already more willing to play in various settings and styles, appealing to the "new eclecticism" I alluded to above. I think So Percussion is a great example of this--they aren't afraid of mixing classically rooted compositional techniques with a popular aesthetic. I think their collaborations with Dan Deacon and Matmos are prime examples of this, and the minimalist-pop style of Jason Treuting's compositions are really beginning to define the sound of this group.
Whoops, I didn't mean to write an essay here, but these things that you've brought up are things that I think about a lot. It is an exciting time to be a percussionist, but it's an exciting time for music in general. Music's role in society is changing in a big way; I think we all need to take advantage of what our discipline has provided us to keep up with these changes so that we don't get left in the dust, clinging to a tradition of music that may very well be reserved for the textbooks soon.
I'm particularly interested in this idea of "new eclecticism;" the more I think about it, the more I want to shape my career around that concept. Thoughts?