I believe there is a musical language shared, roughly, across the entire Western classical music tradition from before Bach to Mahler and beyond. It is the history of progressive introductions of dissonances to mathematical foundations reaching back to Ancient Greece and beyond. This musical language was inherited in American Jazz and, through the Black American experience, recapitulated and enriched with African rhythm in the 20th century. Still later, and perhaps concurrently, Jazz music met other musical traditions and inspirations - Brazil, Iran, India - others.

I was playing O Tannenbaum - Oh Christmas Tree - the other day. The way I will sometimes practice tunes is in the way of Ranier Maria Rilke’s Orbits - that is to say, the tune comes to me from the recesses of my mind, in whatever key I’m currently playing — and I will practice it to the best of my ability, perhaps for a few days. This time, after a bit of practicing it, I was able to play it to a satisfying-enough degree that I felt a quiet warmth - just “that was beautiful”. This song is simple enough at the surface but offers the opportunity for rich, lush inner harmonies that introduce just such dissonances - offering to realize the dream of this entire musical language in just the one song.

I kept practicing. But that day, after playing it, I had this little étude idea come to mind, based on the diminished chord. It is so fundamental that it can easily serve as an intro to a piece such as Misty or Someday My Prince Will Come.

The diminished chord is a “symmetric” chord in the sense that it is built of two equal intervals - two minor thirds. That means that physically on the piano there are “only three” of these diminished chords. Of course they still need to be learned in all keys in their various functions. I kept playing my little étude over the next few days, meditating on “how can I think of these chords so that I can really know and come to wield them freely in my playing?”

This morning I sat down at the piano to think concretely on that question. It turns out that the three physical chords are the “leading tone” or “7 chord” or “passing diminished chord” leading to the three most fundamental triads in any key: the I, ii, and V chords.

As always, what’s exciting to me about this little bit of learned theory is that - first and foremost - it is driven by the music and not by a thought exercise - it comes from a lingering doubt in my playing that I am “missing” the diminished chord and that I can vaguely feel that the real masters of this craft - the people who spoke the language freely - do have a sense of this chord. And now here is a seemingly fundamental way of integrating it into my playing, into the spoken language, into the beautiful music.