Most students will want to get straight to playing something, maybe some particular song they like. This is a mistake. Theory can be kind of tedious, but it is essential. The human mind learns most quickly and thoroughly by associating new information with information it already understands. We must build a framework of basics and build upon that. Take the time to go through the theory lessons. Make sure you understand this stuff. It will pay off big later.
The Physics of Sound
Believe it or not, music is a complex set of mathematical relationships. Thankfully you do not have to be a mathmetican to understand it well enough to be able to make good music. But you do need to understand the basics, so you can understand the language in which music is communicated. The reality of perceived music is the result of the physics of vibration. Rather than getting an advanced degree in Physics, the musical community of ages past has worked out a system of symbols with which musicians and students can communicate sound concepts with one another. You will need to learn this “language” up front, so you can take advantage of the numerous learning resources on the web and in music shops. It will be worth the effort!
When you pluck a string on a guitar, the string begins to vibrate back and forth at a certain rate. We refer to one complete back and forth motion of a string as a cycle, and we express the rate of vibration in cycles per second. We call this quantity of cycles per second frequency, and we use the term hertz as shorthand for cycles per second. So if we say a string is vibrating at a frequency of 440 hertz, this means it is moving back and forth at a rate of 440 cycles per second. So what does this have to do with anything? You will see when you try to use an electronic tuner, just take it in for now.
The frequency at which a plucked guitar string will vibrate depends on several factors: string thickness, length, and how tightly the string is drawn. You can see this easily enough on the guitar. Pick any string. Grasp the tuner key associated with that string, pluck the string, and turn the tuner key. As you loosen the string, you will hear the frequency drop. As you tighten it again, you will hear the frequency increase. Now hit the thickest string, and compare that to hitting the thinnest string. Hear the difference? The thinner string vibrates faster, and we perceive this as a higher sound, or higher pitch. Now, put your index finger down behind one of the lines (frets) crossing the neck of the guitar, effectively shortening the string, and hit that string. Compare that sound to the same string plucked without your finger holding it down. Can you hear that the held string has a higher pitch?
Ok, what does this have to do with making music? You have to have the guitar strings set to the right frequencies if you want the notes you play to sound out at the correct pitch. Otherwise, all the chords and scale paterns you will be learning will not sound out as intended. So muddle through this, we will get to the good stuff soon enough!
So, how do feel about memorizing a chart that shows all the frequency values of the notes at each fret on the guitar neck? Yeah, us too.
That’s why musicians of old figured out a simple system of letters and symbols to represent the numbers. Letter as numbers? Does that sound like algebra? Well, it’s not that complicated. Let’s look at the basic lettering system of music, then we’ll come back to the standard guitar tuning.
The Musical Alphabet
Our English language uses twenty-six letters to represent sounds. The written language of music uses seven letters to represent pitches. Just as we use the letter ‘A’ to represent the sound of a certain movement of air through the mouth, in music we use the letter ‘A’ to represent the sound of a certain frequency of vibration. The A pitch, or note, represents the sound we perceive when we hear a vibration of 440 cyles per second, or 440 hertz, as we discussed before. This value was arbitrarily decided long ago, we just accept it today. The musical alphabet consists of the letters A-B-C-D-E-F-G. Each of these letters represents the sound of a vibration of a certain distinct frequency. These vibrations may come from a string, as with a guitar or piano, or they may originate from within a wind instrument like a flute or clarinet. Either way, the rate of vibration of 440 hertz will be an A note. Similarly, a B or C or D note is always the same frequency of vibration, regardless of what kind of instrument the vibration is coming from. This is why we must tune instruments to the same standard. When the song calls for an ‘A’ note, all the instruments must sound off at the same frequency. Otherwise, we have noise rather than music.