Wednesday, May 19, 2010

Environmental effects

I had an interesting experience in the impact of weather on reeds, something I guess I've heard of, but hadn't really believed. I'd practiced yesterday morning, and my reed (G5) was behaving. But the day was hot, reaching +33 C in the afternoon. Here that often brings rain. I had a rehearsal in the evening, and we heard thunder, and rain came through. And my reeds were terrible. Fuzzy, difficult to make respond. They turned funny shapes too, and closed down. I switched to G7, which is a little lighter, and that helped a bit, but I struggled through the whole rehearsal. My sinuses felt stuffed too, whether that's due to the playing or the weather I don't know. This morning is cooler, overcast, but with a muggy, oppressive feel. I feel like I'm in Europe, London or Paris or something. Or San Diego, which often felt this way. But that's what the weather looks like, why would it affect the reed?

Here are some plots of weather conditions over the past day.

The rain began around the start of my rehearsal at 1900, right in the middle of these plots. The shifts in temperature, wind and humidity are substantial on these scales. The pressure, which seems like a natural candidate to impact acoustics, doesn't change all that much, going from 100 to 100.5 kPa, a 0.5% shift. The humidity, on the other hand, changed from 20% to 70%, which is more than a factor of 3. So is it the humidity? Dunno. It's not obvious to me how that would work. After all, the reed gets fully saturated with water when it's soaked, so why would a slight shift in external humidity change its shape or properties? Or would it be due to the humidity in the air column of the instrument bore? That air is all exhaled breath, which I'd think is generally saturated with water vapor regardless of the external humidity. Curious.

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