Music: decrescendo vs diminuendo

The tutor clears up an issue he’s wondered about for years.

As a kid I was trained in music. Two of the first terms we learned were crescendo and diminuendo. Crescendo meant getting gradually louder, while diminuendo meant the opposite: the the gradual change from loud to quiet. Others I’ve talked to agree they were taught the same.

Since about ten years back, I don’t hear people say diminuendo; instead, they say decrescendo. While the term makes sense, why has it replaced diminuendo? With the curiosity of an academic, I resolved to find out.

According to the website the-difference-between.com, diminuendo actually means the mark that indicates gradual change from loud to quiet, or else it can point to a passage of music over which the volume adjusts gradually from loud to quiet. The actual trend of going from loud to quiet is decrescendo.

The distinction between diminuendo and decrescendo is subtle enough that I can understand why, as kids, some might only have been taught diminuendo.

HTH:)

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Plant identification: elder(berry wine)

The tutor shares a backyard find that is somewhat coincidental.

For an unknown reason, I decided to listen to Elton John’s song “Elderberry Wine” on YouTube the other day. It’s a great song; I’ve just never felt moved to look it up. I heard quite often from a vinyl record decades ago.

At the same time, there’s a tree growing in my abandoned garden (very good soil, just no time to plant it) that I’ve been wondering about. Not long after hearing “Elderberry Wine”, I happened to be thumbing through a field guide when I stumbled upon elder. There were three varieties: black, blue, and Pacific red. Elder, the guide points out, is also referred to as elderberry.

The elderberry description matches the tree in my backyard – especially that of the blue elderberry. It would be tempting to assume the tree to be Pacific red, but it doesn’t have an unpleasant odor. The leaflets, saw-toothed and pinnately compound, occur in groupings of nine, rather than five to seven. The ecology – a cleared, yet neglected place – more closely matches that of blue elderberry as well.

Of course, the real test would be the colour of the berries, but there’ve not been any; perhaps the tree is too young to flower. I guess we’ll see.

It’s tempting to imagine that tree out in the backyard, with strains of “Elderberry Wine” reaching it through the open window:)

I’ll be sharing more of my field finds.

Source:

Little, Elbert L., Susan Rayfield and Olivia Buehl. Audubon Society Field Guide to North
   American Trees, western region. New York: Knopf, 1986.

Pojar, Jim and Andy MacKinnon. Plants of Coastal British Columbia. Vancouver:
  BC Ministry of Forests and Lone Pine Publishing, 1994.

Elton John. “Elderberry Wine.” MCA Records, 1972.

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Physics: the wavelength of “middle” F

Tutoring physics 11, this topic comes up most years.  The tutor introduces the formula that relates speed to wavelength and frequency.

Most people know that what makes sounds different is that they have different frequencies.  Moreover, a high pitched sound has a higher frequency than a low pitched one.  Likely, that’s whence the idea of “high note” vs “low note” originates.

Every wave has not only a frequency, but also a wavelength.  The two go hand in hand according to the formula

    \[v=f\lambda\]

where
v means velocity (which, for this purpose, can be reduced to speed),
f means frequency
λ means wavelength

Dividing both sides by f, we arrive at a formula for the wavelength, \lambda:

    \[\frac{v}{f}=\lambda\]

As I mentioned in my January 13 post, the speed of sound s is given by

    \[s=(332 + 0.6T)m/s\]

where T is the temperature in degrees Celsius.

Let’s imagine, for temperature, a pleasant 20C. We have, for the speed of sound,

    \[s=(332+0.6(20))m/s=344m/s\]

Since speed and velocity are, for this purpose, the same, we can say that v=344.

Next, we need f, the frequency. Specifically, in this case, we want the frequency of “middle” F, which is meant to be the F just three keys above middle C. The physics dept at Michigan Tech provides this handy page, informing us that the F above middle C has frequency 349.23Hz.

With v=344 and f=349.23, we are ready to find the wavelength of middle F:

    \[\frac{v}{f}=\frac{344}{349.23}=0.985m=\lambda\]

Therefore, the wavelength of middle F, at 20°C, is 0.985m or 98.5cm.

HTH:)

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.