Music Theory – Crash Course
So, you’ve been making noise awhile now and are probably making noise with others… and there is always that one guy that compliments your dissonant third. Um, I think that was a compliment, right? Seriously, though, while it’s not necessary to make rocktastically euphoric songs, an understanding of basic music theory helps to communicate ideas with others.
Music theory is a very broad subject. Fortunately, for 98% of us, there are four topics: pitch, rhythm, melody, and form.
Pitch is what you hear. It is the tone, register, key, and scale. A long time ago in a place far, far away; western culture divided sounds into twelve tones… C D E F G A B with the semi-tones of Bb, Eb, Ab, Db, Gb. And by decree, the A above middle-C is 440 Hz (concert pitch). All that means is get yourself a modern tuner and everyone is on the same page.
Sound is a pressure wave of air hitting your ear and vibrating your brain. If you measure the vibrations per second, you get the audio frequency. A perfect human ear can hear from 20 to 20,000 Hz. Bass runs up to about 250 Hz with anything below 40ish being subs (felt). Vocals range from 300 to 3000 Hz with frequencies up to around 6000 Hz adding color. An oddity is that the fundamental tone of the voice is below the vocal range (reason #1 why bass is so important). Cymbals and such range around 10000. Other instruments mish-mash all over the spectrum, particularly guitarists. Boiling it down, register is the octave and EQ of the sounds you are making… if two of you make sounds in the same frequency range, it will tend to puddle.
The key and scales are what bind the song together. There are 12 keys. Humans find certain combinations of tones more pleasant. Easily half of all the music you have ever heard is in either Gmaj, Cmaj, or Dmaj. The mind blow is that the 1-4-5 chord progression for Gmaj is G C D. The key of G is also known as the Queen’s key or Folk key… so if you are called to the Castle to throw down a tune, G is a good choice. The point is; everyone needs to work in the same key (unless you are going for that dissonant third sound).
Rhythm is when you hear. This is the meter of the music; the tempo and speed at which to make sounds. Genre of music are broad brushed into tempo groupings as measured in beats per minute (bpm). Our bodies are ticking clocks. At 60 bpm we are sleeping; at 100 bpm we are active; at 120 bpm we are running; at 130 bpm we are making copies of ourselves. Boiled down, everyone needs to count at the same rate so that your audience can groove.
Melody is why you hear. This is such an abstract concept which brings together chord progression, harmony, timbre, color, and dynamics into a pattern that makes you… hum the tune. I’ve generally found it difficult to translate a melody into speech with another musician. There are two ways to do it; either write it out in musical notation or play a few bars for them.
Form is how you hear. The structure of the music; the arrangement of verse, chorus, and bridges. The density and texture of sounds and their reverberations. Whether the rhythm and melody are to be played in 12bar blues or in a free-form jam determines the overall structure and form.