Found Chord

We've lived in St. Louis just over five years. In our first house, we lived a mile or so from Interstate 64/U.S. 40, and now we live about the same distance from Interstate 44.

In both our houses, if the day was still, every so often I could hear a kind of chord made by the indistinct but audible sound of interstate traffic and the hum of neighborhood lawn mowers in the distance. I don't want to equate an industrial sound with the Hindu idea of "om," the primordial sound of the divine, universal consciousness, intoned in prayers and mantas. But there was a strange peacefulness at hearing a tone in the air on a bright morning, especially when the more natural sound of birds accompanied it.

I'm sure the sound has been different each time, but yesterday (now that our piano is tuned), I approximated the chord. I apologize for not knowing enough music theory to name this chord, but in the treble clef it is the B-natural below middle C and up to F-sharp, and in the bass clef it is the D below middle C and down to F-sharp. I thought of my dad, who provided for our family with his life work as a truck driver. He liked the sound of traffic on highways, for him a familiar euphony.