An Expert Musician

For the second unit of my STEAM course, "Light, Sound, and Time," we were assigned to create our own guitars, or "diddley-bows." This unit deeply revolved around how sound travels and the speed it can reach. We explored many math concepts that helped us along our road of understanding the background of sound. We studied key concepts that play a big part in the traveling and manipulation of sound as well. For example: studying how as the frequency of sound increases, the wavelength decreases and theories related to that. I loved the versatility and flexibility of this project. The creative control of the guitar allowed us to tamper around with materials. Getting the string very straight and firm was the hardest part. This consisted of a lot of screw driving!

DR "My Diddley-bow," Photo. 03/02/16

DR "My Diddley-bow," Online Drawing. 03/02/16

Above is a diagram labeling each part of my guitar. Relating my diddley-bow to a real guitar, the tin can represents the resonator, the wood represents the neck, and the battery represents the nut.

The golden question is, how does this mediocre looking guitar actually produce sound? The string vibrates as you pluck it, creating a longitudinal wave which allows molecules to travel as sound, to your pinna. There is also the tin can, which allows you to hear the sound better because it amplifies it for you. Connecting the science of the "diddley-bow" back to what we learned throughout this unit, this homemade guitar is sending sound waves out; not only that, but the versatility of the string allows you to change pitch and frequency. Can’t forget that as the frequency changes, so does the wavelength. You can use a slide to change the frequency as you pluck the string. The amplitude of the string increases and decreases when playing the guitar.

The Doppler Effect is when an object has a higher frequency and lower wavelength when approaching another object, but as it moves farther away from this other object, there is a lower frequency and higher wavelength. For ex: while moving towards a person or object, the frequency of your guitar is increasing because you are getting closer.

In order to assemble my diddley-bow, I used a string with a thickness of 0.035 inches and a length of 9 inches. To get the volume, I first had to find the radius of my resonator. Since the diameter was 3.5, the radius was 1.75, and to find the the volume of the amplifier, I had to do pi x Radius(squared) x Height. My volume came out to be 38.48 inches (cubed).

DR "The Harmonics," Online Drawing. 03/02/16

Above is the listed harmonics in order of highest wavelength to lowest. These harmonics originate from the actual sound of my guitar, where I used an online program to record the frequency of it.



If I could do it all over, I would definitely explore ways to customize my project a bit more and I would have also explored options of making my wire a lot more firm.