The modes: major and minor

A mode is the particular makeup of a diatonic scale, that is, the way its whole steps and half steps are arranged. So far you have met only one mode, the major mode. Now let's meet a second one, the minor mode, which places its half steps elsewhere. (In British English, half steps are called semitones.)

A quick review of the major scale

Let's start with what you already know. In the diatonic major scale, the two half steps lie between the 3rd and 4th degrees, and between the 7th and 8th degrees. Now look at two intervals that the tonic forms with other degrees:

• the tonic and the mediant (C to E in C major) form a major third;
• the tonic and the submediant (C to A) form a major sixth.

What changes in minor

In the minor scale, that third and that sixth are minor. So to turn a major scale into the minor scale on the same tonic, you lower the mediant and the submediant by a chromatic half step, which British musicians call a chromatic semitone.

Now compare the two scales degree by degree. Apart from the third and the sixth, which are major in one and minor in the other, every other degree forms exactly the same interval with the tonic: a major second, a perfect fourth, a perfect fifth, a major seventh and a perfect octave.

The three diatonic half steps of the minor scale

Because of these two changes, the minor scale we are studying here contains three diatonic half steps instead of two. Here is where they lie:

1. between the 2nd and 3rd degrees (D to E♭);
2. between the 5th and 6th degrees (G to A♭);
3. between the 7th and 8th degrees (B to C).

Between the 6th and 7th degrees, from A♭ to B, you'll notice a gap wider than a whole step. That is an augmented second, and we'll look at it closely in the next lesson.

The modal notes

The mediant, or 3rd degree, and the submediant, or 6th degree, lie at different distances from the tonic in the two scales. So they are the notes that define the mode, and that is why they are called the modal notes. Degrees I, IV and V, by contrast, are the tonal notes, which you met in Lesson 1 of this part. Listen now to the two chords, then to the two scales.

Now that you can hear the difference between the two modes, the next lesson shows you where the minor scale actually comes from.