All composers are products of their times, and their scope and vision of Humanity is confined by the strictures of those times. Too, some of the most promising of them had very little time within their "time". This said, I propose Franz Schubert as one who "reached the greatest depths, breadths and diversity to humanity in all of their subject matter." He wrote so many kinds of music, from light dances to probing symphonic movements, from solo piano contemplations to chamber music conversations, from large choral masses to some of the finest miniatures in the repertoire, and he did so on a diversity of topics, secular and religious, light and dark, observational and speculative.
Schubert has always seemed problematical to me. Among his most accessible works, one with an almost instant "appeal value", is one which ranks also among his most profound musical essays: the Unfinished Symphony. This single work seems to me to probe the deepest recesses of the human experience in all its possibilities and textures. I can never but listen to it with fresh ears. It haunts my sensibilities and seems to exist in a near "other world" of music, almost as if created by an alien mind distilling all of humanity's history of music into two movements of exhaustive power. Yet, it can be featured as incidental music to a child's cartoon, and has with The Smurfs.
And still there are those piano sonatas and string quartets and dozens of other chamber works and hundreds of songs to contend with. Just considering the songs: they are set to some of the most meaningful verses by some of the greatest of our poets, to words which stand alone with the greatest thoughts of Mankind, and yet the addition of Schubert's music only enhances their power.
I recall, decades ago, telling groups of students that Schubert, who died so young, was among my favorite composers but that I didn't comprehend his music. It always seemed too deep for my grasp. It seemed like music that was written by the oldest and wisest and most experienced person in our species and that I would have to wait until I had many more years of age, wisdom, and experience myself before I was able to even graze the surface of those profound depths. I remember telling students that I was collecting discs and scores of Schubert's music with the intention of someday being able to approach it with some better level of understanding. And now, several decades on in my own life, when I turn to the music of Schubert, I realize that it still escapes me. But I understand now, too, that I could never achieve the level of empathy for the human experience that had come naturally to Schubert, through that inexplicable, ineffable gift we call genius.
I once read something to this effect: Schubert, who lived only 31 years, composed a nearly impossible amount of music, largely within a span a fifteen years. In fact, if one calculates the time it takes to jot down Schubert's body of work with ink and a feather pen the task seems nearly to take a full 15 years, working 20 hour days. Did Schubert ever eat and sleep and do anything else but scratch down notes on manuscript paper? Yet, given this ... and this is the most startling statistic of all, to me ... nearly everything Schubert ever wrote ranks as a masterpiece. How is that possible?
So, which composer "reached the greatest depths, breadths and diversity to humanity in all of their subject matter?" I don't hesitate to respond: Franz Schubert is my selection.
