Music Theory

So what's to know then, eh?

Music as we know it (it is widely believed), was invented by the philosophers of Ancient Greece - the man who played perhaps the largest hand in the development of "blending harmonic sounds" was Pythagorus (the bloke who invented triangles... err, right...). For it was he who discovered that a stretched wire would produce a sustained sound when plucked (just like a guitar), and that this sound would change when the tension in the wire, or the length of the wire, was changed.

His first major discovery was that two equally stretched wires (one being TWICE as long as the other) would produce the same 'NOTE' (i.e. the type or 'PITCH' of sound) but the longer one would be much lower (what we now refer to as an 'OCTAVE' lower). A similar situation can be shown by pressing two keys on a piano keyboard that are seven white keys apart (see the picture below for the two keys called 'C'). The resultant sound is 'pleasurable to the ears' (as Pythagorus put it), and you can hear that the two notes are the same but one is lower than the other.

Pythagorus experimented for many years building wires of varying length that produced 'pleasurable' sounds when plucked together. You can get a feel to how he decided what was 'pleasurable' by playing the notes 'C' and 'E' on a keyboard at the same time, and then comparing that to the sound produced when you play 'C', 'C#' and 'D' together... You notice quite quickly that the former pair seem to 'blend' their sound together while the latter group seem to work against eachother (making an "eurghghrr!!" type-noise).

After many years of work, the Greeks designed instruments using varying lengths of wire. The simplest using a several wires ranging from a short piece, to another piece of wire that was twice as long. Eventually they hit upon a standard using 13 wires where the notes produced would go up in equal increments when you plucked them in order. Today we call these increments 'SEMI-TONES'. If you look back up at the keyboard diagram you will see that going from one 'C' to another 'C' (inclusive) requires 13 keys (white and black).

All the keys on a piano keyboard (white and black) go up in Semi-tones, so we can say that two notes of equal pitch are separated by 12 Semi-tones.

N.B. Beginners often don't realize that the difference between a white key and a black key that are next to each other (e.g. C and C#/Db) is the same as two white keys that are next to each other (BUT WITHOUT A BLACK KEY IN THE MIDDLE - i.e. B and C, E and F); they are all one Semi-tone apart! It took me 13 years of playing music to realize that - no one had ever actually explained it to me.

Scales?

It was from this layout of 12 Semi-tones that the Octave (i.e. the EIGHT - 'octa' - white keys on the keyboard going from 'C' to 'C') was defined; and it is from these 12 Semi-tone increments that 'SCALES' were defined.

Scales are basically strings of notes/increments (played consecutively) that begin on a specific note ('C' for example) and finish on that same note one Octave up or down. There are many such Scales in music, each has a specific name that supposedly reflects its sound and/or structure...

The Chromatic Scale

The simplest of these is the 'CHROMATIC SCALE'; this Scale consists of all the white and black notes between two notes. To play it just play all the notes between two 'C's, or two 'E's, or two 'F#'s, etc... You see, a Scale is defined by the increments in which the notes go up, so you can play the Chromatic Scale corresponding to any note just by playing all the keys between two notes that are an Octave apart.

So if you start on 'A' (for example) and go up (or down) in Semi-tones until you reach the next 'A' (i.e. play all the keys between them), then you have just played the 'CHROMATIC SCALE in A'. If you start on the 'Bb' and do the same you will play the 'CHROMATIC SCALE in Bb'. It is the same for all the notes... as long as the string of increments within an Octave is the same you can play the same Scale for any note you want. In the case of the Chromatic Scale the increments are all Semi-tones.

So how about that? We've barely started and you already know how to play all 12 the Chromatic Scales: Just start on any note you want and go up or down in Semi-tones... 

Chromatic Scale in C       C  C#  D  D#  E  F  F#  G  G#  A  A#  B  C
Chromatic Scale in C#/Bb      C#  D  D#  E  F  F#  G  G#  A  A#  B  C  C#
Chromatic Scale in D              D  D#  E  F  F#  G  G#  A  A#  B  C  C#  D
Generic Chromatic Scale            st  st st st  st st  st st  st st st  st

st = Semi-tone

Looking at the Scales written above and the keyboard picture again we can see that it is the difference between the notes (the increments) that define the Scale. Once that is known we can play that particular Scale starting on ANY note.

Similarly, this is how other Scales were defined; some of which you've probably heard of...

The Major Scale

The 'MAJOR SCALE' is defined as: 

Generic Major Scale       t  t  st  t  t  t  st

t = Tone = 2 x Semi-tones.

So starting on 'C' the Scale would go: C, D, E, F, G, A, B, C. If you play it you will see that the Scale sounds 'happy' or 'agreeable'. And this is why the piano keyboard is designed as it is; to make it easier to play the 'C' Major Scale. Note that black keys do not occur between two keys that are only a Semi-tone apart, i.e. B and C, E and F, since there are no more notes to be played within a Semi-tone increment. The black keys are called 'ACCIDENTALS' (the white keys are called 'NATURALS'), and are refered to as '#'s ('SHARPS') or 'b's ('FLATS'). As you've probably already guessed a Sharp is a Semi-tone higher than the white key is named after, e.g. F# is a Semi-tone higher than F, and a Flat is a Semi-tone lower than the white key it is named after, e.g. Gb is a Semi-tone lower than G.

Because a black key is surrounded by two white keys it always has two names, e.g. the more observent of you will have noticed that F# and Gb are the same key!! You may like to know that two notes with the same pitch but different names are refered to as 'ENHARMONIC'. But then again, maybe you wouldn't... It is also possible to refer to white keys as Sharps or Flats (e.g. B can be called Cb, and C can be called B#) because the terms only refer to the difference is pitch; however, this is rare in piano-playing, and I have NEVER heard it used in harmonica-playing.

Now try to play the Major Scale in F#... Think you can't do it? Just follow the rules, starting on 'F#' and going up; Tone, Tone, Semi-tone, Tone, Tone, Tone, Semi-tone. You will see that this Scale also sounds 'happy' or 'agreeable'. Remember that a 'TONE' is the same as going up TWO keys at once! 

Major Scale in F#/Gb       F# G# A#  B  C# D# F  F#
Generic Major Scale          t  t  st  t  t  t st

The Minor Scale

The other Scale you've probably heard of is the 'MINOR SCALE'; this one negates the Major Scale by sounding 'sad' or 'melancholy'. The Minor Scale is defined as: 

Generic Minor Scale       t  st  t  t  st  t  t

t = Tone = 2 x Semi-tones.

You've probably noticed that this is equivalent to taking the last two increments of the Major Scale and sticking them on the front. So if you play: A, B, C, D, E, F, G, A, then you have just played the 'MINOR SCALE in A'.

So you could play the same string of keys (i.e. all the WHITE keys) and you could get two different sounds depending on which key you started on ('A' or 'C'). Clever, isn't it...

So what have we looked at so far? Well, you now know the origins of modern music, the history of harmonic development, and you can now play 36 different Scales (12 each of Chromatic, Major and Minor).

Not bad for half an hour...