Considering that you could spend four or five years in university getting a degree in music, and still not know everything, it is difficult to explain music theory without getting into long, boring explanations.  But since digital media involves music I'll have to start somewhere, so here goes.

We know that sound is the result of our ears detecting moving waves of air started by some vibrating object.  We have all experimented with hitting a ruler while sliding it along the edge of a desk. (If you haven't done this, wait for Math class - don't do it here!).  We know that the faster the ruler vibrates the higher the "pitch" or frequency of the sound will be.

What's the difference between noise and music?  Well, when you consider Rap, not much!  Sorry, I'll try to be more objective.  Music could be considered the result of pleasing sounds, while noise could be considered displeasing, or annoying sounds.  From a physics standpoint, noise sound waves have more irregular patterns or frequencies than musical sound waves.

Musical Notes and Scales

Recognizable musical notes have specific frequencies. If you play in the school band, you have probably heard the term "A 440".  This refers to the note A, above Middle C (picture a white key about half-way across a piano keyboard) that has a frequency of 440 cycles, or vibrations per second. If you were to continue up the keyboard playing the white keys, you would reach another note that sounds the same but with a higher pitch. This would also be an "A" but with a frequency of 880 cycles per second. You would have played an "octave" of notes, or eight full tones from the lower A to the higher A.  The notes that you played on the way up to the higher A are named A-B-C-D-E-F-G, then the other A.  Click here to review Sound Editing Basics.

A musical scale made up of the first seven tones, (the white keys on the piano keyboard),  and five semi-tones, (the black keys), is called a Chromatic scale. The pitch ratio between any two successive notes of the scale is exactly the twelfth root of two. The frequency of any of these twelve notes will be the frequency of the one before it times 1.05946, in case you're wondering. For example, the frequency of B would be 440 X 1.05946 = 466 Hz, or cycles per second.

Music Terms

Notation - a system of writing music so that musicians can read and interpret how the song should be played. In a way, it's like a musical graph, with lines of a "staff" divided into "bars". The up and down location of the notes along the staff indicate the note, (A, B, C, etc.), and the bars  represent the time, in beats.

The Treble Clef staff shows what is usually played with the right hand on a piano keyboard, and is used by most instruments. In this example there are four beats to each bar.
Harmony - when two or more notes of specific intervals apart are played together. Harmony adds a richness to a song, particularly in the vocals, when backup singers sing a harmony to the lead singer.  Think back to the last assembly when several hundred voices sang the national anthem.  When everyone sings the same part it is called singing in "unison".  Although it might be loud, it is musically quite simple. Now listen to a band from the olden days, (my generation), Kansas, singing a five-part vocal harmony in the introduction of "Carry On". (click here)  You can hear the obvious difference.

This is what notes played in harmony would look like.

Chords - chords are made up of three or more notes played simultaneously. They are named after the "root" note in the chord.  For example, a C major chord uses C - E - G, the 1st, 3rd, and 5th note in the Major scale. There are also different types of chords, depending on the intervals between the notes used in building the chord.  There are also Minor chords such as Cm, which uses C - Eb - G, the 1st note is the same, the 3rd is a semi-tone lower, and the 5th is the same.  These two chords have a significantly different musical 'feel' to them.

The first, fourth, and fifth notes of a Major scale can determine the "Key" that a song is played in.  If a song is said to be "in the Key of C" the primary chords of the song are C - F - G.

These are the three main chords found in the Key of C.


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