Each tetrachord consists of four notes of a scale. You must order the tetrachords in order to build each Major scale with flats in the key signature.

Each scale is made up of two tetrachords, each with four notes.

The first tetrachord of the C Major scale is C, D, E, F. The second tetrachord of the C Major scale is G, A, B, C. Mouse over those tetrachords below to hear them.

Each tetrachord consists of notes arranged a certain distance in pitch from one another. Notes in a Major scale can be separated by either a tone or a semitone.

Each tetrachord must consist of the following intervals: Tone - Tone - Semitone. There will be a tone between the first and second tetrachords in each scale. Mouse over the tetrachords again and see if you can hear where each semitone occurs.

The interval pattern for one major scale then should be Tone, Tone, Semitone - Tone - Tone, Tone, Semitone.

Major scales with flats are built by adding one tetrachord BELOW the first. This pattern is the OPPOSITE of that used to build the Major scales with sharps. so you must order tetrachords from the right hand of the screen to the left- descending in pitch.

To do this think of the first tetrachord of C major C, D, E, F and add a tetrachord BELOW this. To ensure your tones and semitones fall in the right places you will have to lower one or more notes and this is where the flats occur.  Eg: 

F (tone) G (tone) A (semitone) Bb (tone) C (tone) D (tone) E (semitone) F.  What scale have we made?

Order the major scales with flats from the right side of the screen to the left. Begin by moving the tetrachords above to the right hand side of the screen.

Now take the first tetrachord of this new scale (F, G, A Bb) and add a new tetrachord below it to make our next scale. Be careful to ensure that the tones and semitones follow the correct pattern.