modes de transposition limitée

Messiaen's system of seven modes (scales) that can be transposed only a limited number of times before returning to the same pitch-class content. Mode 2 (the octatonic scale, alternating whole tones and semitones) and Mode 3 are most frequent in his piano music.

These modes produce a distinctly ambiguous tonal gravity — neither firmly tonal nor freely atonal. Each mode carries a specific colour in Messiaen's synaesthetic perception; identifying which mode is active helps the performer understand harmonic regions as colour fields rather than functional progressions.