They don't always talk about music, but I like these Crash Course videos. They don't talk about free reeds specifically, but it's still interesting. It's got some math but they've got it illustrated pretty well so you don't have to scratch formulas down.
Nice presentation. So I guess a harmonica reed, with an anti-node at one end and a node at the other, can not have even number harmonics, just like a pan pipe.
ON a similar note, I have been demonstrating to the kids I teach that when you cut a guitar string in half by pressing in the middle, the pitch goes up an octave. This is a very easy demonstration to see and understand. The same also holds true for brass instruments. A Bb tuba has 18 feet of tubing, if you make an instrument with 9 feet of tubing, it sounds an octave higher and we call it a trombone (or perhaps a baritone, euphonium or bass trumpet). If you cut the tubing down to 4.5 feet, you go up another octave and we call it a trumpet (or flugelhorn, coronet or soprano trombone). Cut it once more to 2.25 feet and you go up one more octave as a piccolo trumpet.
Good video, but we've been here before - I can see it's tempting to think that, because a lot of instruments make their tones with standing waves in strings and pipes, they all do. But clearly the harmonica reed doesn't. It's a different thing.
STME58 your own FE analysis clearly showed that the reed's modes aren't even vaguely in a harmonic series, which is no surprise as there is no reason they should be. Whereas there is a reason why a guitar string's modes are harmonic.
I know you are a brass player, and if you've read up about the physics of that, you'll know that it's a much more complex situation than the simplified principles in this video to make a usable instrument.
Last Edited by MindTheGap on Aug 13, 2016 2:47 AM
Lately I've been reading about inharmonicity in lamellaphones like kalimbas and mbiras. In those instruments you can actually tune the harmonics separately from the fundamental. It's blowing my mind that the harmonic series isn't actually set in stone.
Here's a site that talks about how to tune harmonics in kalimba reeds.
Yes interesting. There's inharmonicity in other instruments too, the piano for instance.
It's good to understand the simple principles in the video, and they are valid starting points. But it's also good to understand that there are complexities in real-world instruments that go beyond that. I'm no expert but at least I know they are there.
Otherwise people make the mistake of applying these simple ideas everywhere as if they were rigid fact. I don't think you need to know all this to be a good musician, but I'd expect the customisers to be in touch with it. I've even read about custom harps with tiny 'resonance tubes' inserted into combs to enhance the sound, using resonance presumably. Yes, well, if you are a bat.
Last Edited by MindTheGap on Aug 14, 2016 3:26 AM
