Modes of limited transposition facts for kids

Modes of limited transposition are special kinds of musical scales. They were often used by a famous French composer named Olivier Messiaen. These scales are unique because you can only move them up or down a few times before they repeat the exact same notes.

What is Transposition?

Imagine you have a song you like. If you sing it higher or lower, but keep the same tune, you are transposing it. In music, transposition means moving a whole scale or a piece of music up or down to start on a different note.

Most scales, like the major scale or the minor scale, can be transposed in many ways. For example, a major scale can start on any of the twelve different notes (like C, C#, D, and so on). Each time you start it on a new note, you get a new set of notes. This means there are twelve different major scales.

The Chromatic Scale

The chromatic scale is a bit different. It uses every single note, one after another, like playing all the white and black keys on a piano in a row. If you start a chromatic scale on any note, it will always have the exact same set of notes. So, the chromatic scale only has one transposition. It's always the same!

Messiaen's Special Scales

Olivier Messiaen was very interested in scales that had only a few transpositions. He liked scales that, when moved up or down, quickly repeated the same notes. He called these his "modes of limited transposition." He felt these scales had a special, almost magical, sound. He even said they had "the charm of impossibilities."

The First Mode: Whole-Tone Scale

Messiaen's first special scale is called the whole-tone scale. In this scale, every note is a "whole tone" (two semitones) away from the next.

For example, a whole-tone scale might be C, D, E, F#, G#, A#, and then back to C. If you start another whole-tone scale on C#, its notes would be C#, D#, F, G, A, B, and then back to C#.

If you try to start a whole-tone scale on D, you would get D, E, F#, G#, A#, C, and then back to D. Look closely! These are the exact same notes as the first example (C, D, E, F#, G#, A#, C). This means the whole-tone scale only has two transpositions.

Many other composers used the whole-tone scale too. These include Glinka, Liszt, and especially Debussy.

The Second Mode: Octatonic Scale

Messiaen's second special scale is also known as the "octatonic scale." This scale moves up by alternating between a semitone (the smallest step between notes) and a tone (two semitones). So, it goes semitone, tone, semitone, tone, and so on.

Messiaen used this scale a lot in his music. He used it not just for the tunes (the melodies) but also for the chords he created (the harmonies).

The Third Mode

The third special scale Messiaen used follows a pattern of tone, semitone, semitone. This scale has four different transpositions.

Other Modes

Messiaen also identified four other modes of limited transposition. Each of these last four modes has a total of six transpositions.

Messiaen loved these scales because they sound very balanced. When you listen to music made with these scales, no single note feels like the "starting" or "home" note. All the notes seem to have equal importance.

See also

In Spanish: Modos de transposición limitada para niños