Monday, February 18, 2008

The Music Machine


The music machine

A music machine? What on earth would that be?

Is it some thing like guitar, piano etc?

No, they are musical instruments.

CD Players, Mp3 players?

No, they are electronic contraptions converting bits to audible sounds which we know as music.

Sometimes, there are these little machines whose simplicity and utmost completeness enthralls you. We see so many advanced versions of these machines around us, without actually knowing what is happening inside them. The technological advancement of those inherent simple designs often introduces obscurity in their understanding. What if, for once, we encounter one such smallest complete design? How would we feel?

However, before telling about one such encounter I had, I would digress onto something relevant for a while.

When I was a kid, I used to hear that charles babbage was the father of the computer. He designed the first computing machine known as difference engine. I had also heard about these small prehistoric computing machines known as abacus. At that time, I never could have thought that these abacus were the precursors of computers, but we were made to learn this as a fact, which we would obediently commit to our memory. Only later, when I grew older, became wiser (supposedly), I heard about this amazing new form of mathematics known as Boolean algebra, where 1+1 was not equal to 2 and where one could express anything by means of zeros and ones. It was an amazing feeling, I was able to draw the connections between the abacus, the difference engine and the computing beasts that we have today. I knew the basic principles, which are the basic blocks for the advanced machines. It is a very satisfying feeling of knowing something in and out.

Enough of this coffeehousing for distraction, Now coming back to the point!!

Usually, my Saturdays are very quite, soothing and relaxed. I spend most of my time browsing through books in the local book store, or buying food supplies for the next week, or sitting in one of those 17th century courtyards and reading. Little did I know that this Saturday would be one of the most interesting of all other weekends.

I came across some new books, in the section aptly named “Hot off the press”. Its quiet nice to have these bookstores where one can go and read, without actually a compulsion to buy them. For people like me, who are barely able to mange to buy one book a week, it is a boon. After reading a very interesting section from a fictional account of the people of South Africa, I decided to go to the music section.

There it was, I saw it. It was a very small machine, size of two match boxes put over each other. A picture of Mozart adorned the top of the machine, and a small lever like structure was protruding out from the side. I took the machine in my hands, It wasn’t very heavy, although it felt a bit dense for the volume it occupied. I fiddled around with the lever. The picture of Mozart on top meant that some kind of sound was supposed to come out of it. The question was, how? Surely the lever had to do something with it. The shape of the lever clearly indicated it had to be rotated. But which direction, should it be clockwise? anticlockwise? , what if I might break it?

Apprehensively, I rotated this lever protruding out of that cardboard box, and I heard the sound, it was Mozart’s. The sound was so pure, so natural and so subtly wonderful. It was the similar feeling I had when I heard my first classical concert in switzerland. The sound of the metallic pegs hitting the tense metallic strings, amplified by the hollowness of timber of an age old grand piano. The vibrations would travel swiftly to your ears straight from the mechanical interaction. There would be music and your soul. Nothing else. No frequency spectrum corrections from the mixing board, no stupid aberrations because of the limited fidelity of the microphones.

This sound was similar to so many other sounds, the sound of someone playing a musical instrument right in front of you, the sound of snow melting and hitting the ground at 7 in the morning, the sound of a stream rushing through to meet its river. It was fabulous.

So, intrigued by its simplicity and its mesmerizing sound, I brought it home. I took off the cardboard box and saw this amazing machine. I was so impressed by the completeness and inherent simplicity in the design. It was a mechanical contraption producing such a beautiful music. I had seen some of the integrated circuit based toys with recorded music on a chip. The music signals, mainly data (zeros and ones) converted to voltage signals which are converted to audible vibrations by another electromechanical assembly known as speakers.

But, this one was very different. There was no integrated circuit, no bits and bytes, no electrical requirements. On the top of that, the machine had recorded piece of music, around 20 seconds long. The music could be played again and again by a simple rotation of the lever. It was different from the rattle toys for kids, as the rattle toys emit a very repetitive random piece of sound. But, here was this machine which had an intelligent piece of music recorded on it. I am not sure if the word “recorded” would be the right one to describe those protruding dots, but I guess it would suffice.

Now, the design of the machine: The lever protruding out of the cardboard box controls a metallic drum with small bulging dots on the top of it. There is no seemingly fixed pattern of those dots. They seem to be haphazardly placed, no visible pattern. The small gear assembly between lever and the metallic drum is such that every complete clockwise rotation of the lever would rotate the drum by a few degrees. Thus, it would need a number of rotations of the lever, to completely rotate the drum by a complete cycle. The second part of the machine is a small metallic strip which is clamped opposite to the drum. The metallic strip facing the drum side, is divided into 18 small finer strips. The length of strips decreases as we go from left to right. The width of the strips is same as the diameter of those bulging dots. The strips nearly touch the drum, there is a very little space between the bulging dots of the drum and the end of those strips. Thus, whenever the drum moves, the protruding dots would subtly hit the strips, lifting them by a very small amount and the letting it go. This results in vibrations of one or more of those strips and thus resulting in the sound corresponding to that note. However, since each note and the sound produced by it is only a small part of a bigger melody. The melody can be heard by repetitive rotating of the drum, thus a series of notes can be heard. And that’s the music stored in the form of those protruding dots.

I have shown a basic schematic of the machine below. As one can see the metallic drum with musical notes written in the form of protruding dots. This is where the melody (music information) is stored. The metal strips of varying lengths are also shown. The longest strips correspond to the notes of low frequencies, while the frequency becomes higher and higher as the strips become shorter and shorter. The lever is used to rotate the cylinder, thus the protruding dots come in contact with the metal strips and produce music.

For the sake of comparison with the actual machine, I am including the picture of the actual machine itself.

One can see that this machine can be used to play any musical piece. I am still not able to identify the reason for precisely 18 metallic strips. One simple explanation for this could be the following: The human ear can not identify between the notes with small difference in the frequency, one can do with a small set of frequencies. Each of this frequency is called as a note. There are 5 basic signature notes, E A D G B. To make music richer one often includes intermediate notes like Eb etc. Thus music can be expressed in terms of these finite set of notes. Probably for this machine, this is the optimal number of notes. One can do a more deep research into the significance of the number 19.

The significance of this machine is in its autonomous and simple design. This was one of the early inventions of Thomas Alva Edison, which finally culminated in the design of the phonograph. The technology of recording and producing music has changed in leaps and bounds over the years. From this kind of metallic drum with bulging dots, to the engravings on a circular disk of metal, to replacement of the engravings by magnetic signatures on a LP record, to finally the finer optical engravings on CD’s with music being represented in a sequence of zeros and ones.

However, According to me this still would the most purest and elegant way of listening a piece of music. The reasons are plenty. If we look at the present technologies used to record and reproduce music. The quality is degraded at various steps. The mapping of a continuous waveform to discrete samples while digitizing music incurs what is known as quantization noise. The fidelity of music speakers also contributes to the degradation. There are lots of other factors like compression formats, encoding techniques etc.

When I was in college, I and my friends used to compare the quality of various headphones. Which one has got the best bass response? Which one’s can reproduce all the notes present in a Beethoven sonata? Which one is capable of reproducing even the feeblest sounds present in the music?

Now just imagine, there are no headphones, no encoding and no digital storage. Only the music in is purest form and your ears. Won’t it touch your soul!!

I was discussing this with a friend of mine that probably, if we were to leave some kind of a machine for the future generations, a machine that could last for millions of years, so if incase there is another ice age, we can pass on our music to them. This could be that machine.

If we draw parallels with mathematics one can simply view this machine containing the eigen vectors (the metallic strips) corresponding to different frequencies. The dots on the machines are corresponding magnitude values for those frequencies.

One can draw as many possible parallels. Isn’t it.

In the end, some open questions?

1. Can this kind of machine be used to store human voice? What would we need to change in the design of this machine? More metallic strips (more frequency components)? More detailed markings on the drum? A mechanism to control the speed of rotation (to control the tempo)?

2. Improvement in design for amplifying the sound? Including a hollow chamber to amplify the vibrations?

3. Can this machine be used as a simple educational model for kids? I bet that even in our age, if we analyze the details of it, we can understand and learn a great deal about physics. Isn’t it.

4. A mathematical model for this machine? Could be an interesting work?

5. Can different materials be used instead of metallic strips? What could be their physical limitations? (Length factors etc).

3 comments:

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Anonymous said...

Thanks for the nice article - Elie

Kenny said...

Hey, Thank you for this post, and the fun I had in reading it! My interest in finding out a bit about the Music box came from trying to help a friend to suggest a project to make in school for his technology n' design class... and hence, (since he'll surely try developing his own piano otherwise!) the music box was a great option. I hope you keep going with you blog. Good luck!