Scales

The word scale derives from the Italian Scala meaning ladder, and in the musical sense is an arrangement of notes which are played on a musical instrument for practise purposes or written down for theoretical study. So scales are arranged usually from one (alphabetical) note of a certain pitch to the same correspondingly note an octave (8 notes) higher (or more than one octave) in ascending (or descending) order.

In 'western' music the smallest step between notes is called a semitone (or half-step) and scales are really different arrangements of tones (2 semitones or half-steps) and semitones.

Major and minor scales are most commonly used in 'western' music and the major scale has the following pattern of tones and semitones:-
C major will start on the note C and be followed (logically) by D, E, F, G, A, B & C.

If you look the diagram of the keyboard and particularly at the notes 'C' and 'D' to the left of the diagram, there is a 'black' note (C#*) in between C & D. This means that the distance between C & D is a full tone (whole-step) as opposed to a semitone. The next note in this scale is E and this also is a step of a (whole) tone because of the black note D#. The notes E and F follow in the ascending sequence and as there is no note (or key) between these two then the interval (distance in pitch) is a semitone (half-step). If we continue through this scale from c to c1 then the order of the tones and semitones will be arranged thus, Tone(c-d) Tone(d-e) Semitone(e-f) Tone(f-g) Tone(g-a) Tone(a-b) Semitone(b-c) [T,T,S,T,T,T,S]
This step arrangement is the same for all major scales whatever the starting note.

*C# D# etc. can also be named Db (flat), Eb etc.
 
 

Below the C major scale is written in the bass clef an octave (8 notes) lower.