There used to be two camps in the composition world: the modernist camp, and the tonal (or populist) camp. Putting it simply, the modernist camp rejected on principle any music with elements that could be perceived as tonal, and the tonal (or populist) camp resented the modernists for their perceived hegemony. Both cared about pitch, but they approached pitch organization in different ways, and identified themselves on that basis. Now things have become more diffuse but also, in certain circles, more polarized. There is a branch of musical modernism, now sometimes referred to as research music, in which music comprises gestures or effects. Concurrently, there are composers whose harmonic language is strictly tonal -- who may not even go outside of a key signature in a given work.
One of the defining features of a composer working now is how much pitch matters in his or her music. Pitch (or, in a broader sense, harmony) -- even if it is not tonal - -can help provide a narrative basis to a composition. The narrative may be linear or non-linear, programmatic or abstract. Pitch has the ability to make a human connection. Harmony that uses a tonal orientation of some kind makes it easier for listeners to connect because it contains sounds they associate viscerally with a certain emotional response, tapping into a deep resonance.
Research music - - music based on a gesture or process, in which pitch is relatively arbitrary - -might belong in the same category as the strictly tonal music being written today, because the approach to pitch isn't of core importance to the composer of either. Harmonically speaking, they are both coasting. Other elements (rhythm, texture) generate the narrative and the interest. Of course, it’s a matter of degree - -there is a continuum of different music within these aesthetic groupings.
If a composer desires to create something personal, then he or she must face the issue of pitch (or harmony) for themselves, head on. One must carve out one's place in that middle ground. If one is not developing one's personal use of pitch, one is avoiding the issues. The more nuanced and specific one's harmony is, the more personal one's works will sound. I find it challenging to work with students who write tonally and won't be coaxed into including pitches from modal or extended tonality. I approach this by trying to get them to write modally, doing exercises using synthetic scales, or composing with a limited pitch collection, trying to get them to understand that the tonally-oriented music that has entered the repertoire is, most of the time (although not always), more nuanced than a strictly diatonic collection.
It’s simplistic to reject research music. That branch has to be followed as far as it can go. The best of that music will likely incorporate a nuanced treatment of pitch. The ideal, as I envision it, is like a branch from a tree: if you cut it anywhere, you see its grain. Another beautiful analogy is one that a colleague presented me with in a recent conversation about aesthetics: if you cut up a composition and look at a tiny fragment, would you be able to tell it is yours? Certainly, in the case of a work by J.S. Bach, you would be able to tell.
In my music, the approach to embracing the issue of harmony is to develop an expanded tonality that is attentive to tonal implications even if it embraces many more pitches than the triad- - like a spectral array using overtones from over top, respecting the harmonic implications of the notes in the bass while building upwards to where one could use all twelve pitches. This approach relies upon seeking out quiet within daily life, playing the material on the piano as I develop it, listening to how it resonates, carefully refining the disposition of each simultaneity.
It is vital to me to let the ear lead, to remain cognizant of harmonic underpinnings even if my language is not strictly tonal - -to create a sonic landscape where both harmonies with tonal implications and more dissonant ones can co-exits healthily, symbiotically, infused with rhythmical life. The more “out” harmony I can do, but still have a unified piece, the happier I am these days. So you might get a 12-note cluster in the same piece that you have a tonally-oriented tune, but that makes sense to me. I’ve found that jazz theory (added chords, specifically) is one of the most helpful ways to conceptualize this use of extended harmony.
I’m drawn to working with sound masses - - complex, resonant, rich sonorities– and to finding ways for them to juxtapose dynamically with areas of translucence. It’s easy to pile on sonority until it becomes texture. It’s harder to keep things transparent. Transparency, fluidity, and emotional directness are my goals. It’s important for concert-music composers writing now to value harmony greatly, and to cultivate their own specific use of it. It's also important not to be afraid of a good tune, and not to obfuscate by piling on sonority that is harmonically undefined, or has a vague structural role. My own process of cultivating a more and more nuanced and evolved harmonic language is a process of individuation– becoming more oneself.