There are two main symmetrical scales :

- The diminished scale

- The whole tone scale

The whole tone scale

There are twelve major scales (C, C #, D, D # ect ...), but there are only two whole tone scales.

If we start one arbitrarily by the note of C, the other is the one that starts with the note C# .

Indeed, the whole-tone is constructed as follows:

W     W     W     W     W     W     W     ect ...

We see that it's going to work on X5#/7 or X5b/7 chords type , relatively common in music such as bossa nova.

It is quite difficult to make this scale sing, because of its very distinctive sound ( listen to the intro of "You are the sunshine of my life" by Stevie Wonder, to hear a successful use of this range)


The diminished scale

This is the other important symmetric scale .

It is constructed as follows:

W     H     W     H     W     H     W     H     ect ...

There are only three diminished scales :

If, arbitrarily, we choose one that starts with a C, there is that of C #, that of D, then one starts again on the same notes as the former.

Gypsy music uses it much as WH     WH     WH     WH     WH     ... ect ( Reminder : WH = 1 tone )

It contributes to the strong identity of gypsy music.

In classical music and modern jazz, it is used rather in its complete form for quite interesting phrases ...

We will have the opportunity to study this scale when we discuss the improvisation on chords sequences of form II / V / I.