October 17th, 2009 by Andres Gallo

For this, my first tutorial for guitarliving.com, I wanted to start with something of a foundation into theory so that we may build upon this lesson as things get more advanced. Theory though boring at first, will help you open many doors in the world of music. Please keep in mind, however, that theory should be used as a tool or guide, rather than a rule for writing music.

So here goes the first lesson…

Almost 100% of the music is based on the 12 notes that make up the chromatic scale. Each set of these 12 notes is called an octave. These octaves are infinite and repeat with the same harmonic values but at a pitch that’s higher or lower. So if you play all the notes of the chromatic scale, and then you play the same notes in a higher octave, you will find that these notes are the same, but in a higher pitch.

With that said, the space from one note to another is a semitone. And two semitones make up a tone.

The twelve notes of the chromatic scale can be named by their names which correspond to the letters A to G, or by their intervallic relationship by using roman numerals.

For the numerals, think of the “I” as being the “key” (I will explain more on this), and the other numerals, expressing their relationship to that “I” interval or key. The letter naming system is used to mention a specific note, while the roman numerals express the relationship between a given note and the key.

for example when the key or first is C its third is “E”, and its sixth is “A”.

Below, there is a table showing these relationships in different keys. Learning the function of the roman numerals in expressing the relationships between the notes in a given key is crucial before proceeding to the more complex lessons