Barometric Pressure

In my experience, and not everyone may care to hear of such humdrum experience, preferring instead bungie jumping narrations or weekends at Le Mans, summer and its high barometric pressures make for a richer piano tone. At night when storms and low pressure move in, or in winter, when the air is colder and thinner, the sound is commensurately thinner. It's nothing that even good musicians seem to notice, or that listeners will hear, but the differences are glaring at high altitude, where the seasons seem to change every few minutes. Air exerts pressure on the piano, moving its parts away from their ideal positions, and also affects the quality of the air itself, through which tones travel on their way to immortality at the hands of the microphone diaphragm, which finalizes and seals the fate of the pianist's labors.

    Pressure is as unsettling to a piano as temperature. The treble loses its solidity a few days after tuning, even the same night when pressure changes. Then it comes and goes. Generally, a piano likes to be the same pressure and temperature it was when it was voiced and tuned.

    When the wind direction pulled pressure away from the monastery, a large vacuum pocket would form around the lee wall and the prayer room sounded a bit thin. But when the wind shifted direction and became lusher, the equivalent of barometric beach weather, the oppressive walls were enveloped in thicker oxygen, and the piano became richer, even before it was tuned. Brinkerhoff said of it, "It's streamlined right now - but let's wait for oceanic." Sometimes you can hear the air shift, and certain notes become thin for a few seconds, before reasserting their tenuous grip on the air and the ear.