Scales are essentially just groups of pitches. Composers will
use these groups of pitches to create melodies,
or chords. 
It’s important for us to know scales
because they help us to better understand
the music we play, and kind of  figure out why it sounds the way it does and scales also can help
us to  learn music faster.
So for instance, if
you look at this passage, you might just
think of it as a bunch of notes. 
But if you
know your scales, you'll realize that it’s 
actually just a jumbled up F major scale.
and if you've practiced your F major scale, then you can apply that knowledge to playing that passage 
We label scales with two pieces of important information:
the tonic
 and the type of scale. 
The tonic is the first pitch of the scale but more importantly
it's the pitch that our minds consider to
be the resting tone or the home base when
we hear the scale being played in a song. And the type
of scale describes the unique pattern of half
and whole steps that exist between all the
notes of the scale. There are many, many different
types of scales such as: Pentatonic, octatonic,
lydian, the blues scale and the list goes on and on and on. 
Each one
of these scales has it's own unique 
sequence of intervals.
Let's take the major scale as an example.
What makes a major scale a major scale? Every
single major scale has the exact same sequence of intervals: 
The interval sequence goes like this: Whole step, Whole step,Half step,Whole step,Whole step,Whole step, Half Step
A half step is the space between
two notes that are right next to each other,
such as C and C# and a whole step is equal
to two half steps, so like the distance between C and D.
So If I start on D and follow the major scale pattern:
WWHWWWH I end up getting the D major scale. 
So just to be clear there is a whole step between the
tonic and the second note, and then a whole step between
the 2nd and 3rd note then a half step between the 3rd note and the 4th note and so on.
Let's do another one. 
If I start on F and follow the pattern: WWHWWWH
I get the F major scale. 
So you kind of get the idea here,
You can start on any pitch that your instrument can play and follow that sequence 
and you'll end up getting a major scale. 
So just to wrap up,
Scales are groups of pitches that have a special
sequence of intervals between each pitch.
Each scale has it's own unique sequence and
as a result every scale kind of has a different sound to it.
Next we'll look at some practical examples showing how the major scale is used.
