The whole tone scale is a scale of six notes where each tone is separated from the next by the distance of a whole step. Olivier Messiaen called the whole tone scale his first mode of limited transposition because there are only two possible transpositions of the scale. Because each note is equidistant from the next, there is no leading tone that would help establish a tonic note. Instead, the scale creates a more fuzzy, dreamlike environment, in part because it was used often by impressionistic composers like Claude Debussy.