9/28/10 - Fog

Over the weekend it got kinda chilly here in Denton. Saturday night it got really foggy at about 2 in the morning and I was still wide awake, so I went on a bike ride. I don't think i'll ever be closer to floating in a cloud. And the fog made everything harder to see, which made it more beautiful once really noticed it.

Maybe somehow I can tie that into how mallet instruments work.

Marimbas and xylophones and vibraphones all have harmonics, just like any other instrument. There's your hint. Now, can you tell me what the difference is between the three?

Vibraphones are easy, they're made with metal bars, almost always aluminum. But the difference between marimbas and xylophones isn't range or company that produces it. It's the different harmonics each instrument produces when struck.

When you strike a typical marimba bar, you can hear the note it is normally known as (the fundamental) and the note exactly two octaves above it the loudest. There are more overtones, but that's all that really matters. Marimba producers spend a whole lot of time with a lathe or a chisel taking out parts of the bar to tune the rosewood (usually) to its specific frequency, then to add that second octave above.

Xylophones produce a different harmonic. In Europe, they sound the fundamental and the third directly above it, which is why it sounds brighter than a marimba. In the USA, they sound the fundamental and the 5th directly above it, which still makes it sound a little brighter. I can't really tell you why they're tuned differently.

Vibraphones, coincidentally, are tuned to the fundamental and the second octave.

So try it. Just like playing a harmonic on guitar, put your finger exactly in the middle of the bar, touch it lightly, just barely. Experiment and find how to bring out that harmonic, whatever the instrument is tuned to.

Vibraphones get their name from the vibrato produced by the fans in the resonators. Vibrato keeps ensembles from sounding out of tune, hence why the strings always do it (hehe), just a little bit of info. But that's not the only thing you can do to change a vibraphone's sound. You can press in from the edge to the center of the bar with a xylophone mallet (not brass) after striking it to bend the pitch down. You can bow it with a string instrument bow, and that's a cool effect. You can even mimic the vibrato of the fans with your hand by moving it up and down (toward and away from) the bars at whatever speed you desire, or Mark Ford can do it with his mouth. It's crazy.

Anyways. You thought percussion instruments made one note and were always struck. Psh. That's just the beginning of it. When you're forced to look hard, say, through a thick patch of fog, you see things differently when you see them again. And it's pretty great what you can discover when you don't know what to expect.

M