Some basic music theory

Key Signatures and Scales

Key Signatures
A key signature is located in the beginning of the song. It tells you which notes you will have to raise or lower by a half step (a semitone) in the whole song. If there are no sharps or flats visible at ALL, then that means the song is in C Major (or A Minor, but ignore this, we'll get to that later).
You can add up to seven sharps or flats in the key signature, but not both at the same time (unless you want something else than a Major or Minor scale). Determining in which key a song is will be explained later.

Scales
This is one of the most important things in music notation.
You have 12 different (sounding) notes, but you don't have to use them all in the same song (you can, but in common pop songs for example it'll be less likely, unless maybe for a cool effect).
There are several groups of notes, who create a certain sound or atmosphere because of their order and the mutual distances between notes, remember the tones and semitones? I rather like to name these distances intervals, which is the correct musical term. You can use semitones & tones, or whole or half steps.

A scale helps to make a song coherent and easily accessible to the (often) non-musical listener.
Maybe that's why jazz is less popular than pop music, since jazz often doesn't use only one scale?
Anyway, let's see how we note a major scale, which is one of the most common used scales. We will also analyze the intervals in this scale. It are the intervals who give a scale its special characteristics, and you will see that not every interval is the same.

A C major scale looks like this (just look at the height of each note, not the extra lines):



The numbers above indicate the distance to the tonic. The tonic is the FIRST note of a scale (in this case the C), and is also the most stable note (you'll see why later). You will see that after the seven comes a one again, because that is a C. A Major scale contains 7
different tones.
I also added these symbols. They indicate if it is a half or a whole step (a whole tone or a semitone) to the next tone.
C-D is whole.
D-E is whole
E-F is half
F-G is whole
G-A is whole
A-B is whole
B-C is half

These intervals can be found in every major scale.
This is what you will hear in the next audio clip. It will go up the scale, and back down. Note that there is no tension, if the last tone is played, you don't want it to continue. The phrase is over.


Let's hear it:
C Major Scale

If you look at the two different intervals in the scale, the whole and the half steps, you'll hear a difference.

This is what you'll hear next:

Whole & Half intervals

First a whole step (C-D), then the two half steps (E-F and B-C) in the C Major scale, then the first whole step again, and then the tonic (C) and the D, but with a half step (so C-C#, OR C-Db) so you can compare the difference in intervals from the same tone.

If you like this article I would gladly add more to it, depending on what you'd like to learn.