Notes: C, D, Eb, E, F, Gb, Ab, A, Bb, and B - Key: C - Category: Undecatonic or Hendecatonic Scales
The C Messiaen mode 7 inverse uses eleven notes per octave. Because of this same reason it is a member of the so called Undecatonic or Hendecatonic -scales that have Eleven-note (or Eleven-tone). On the piano keyboard, it is made up of four black keys: Eb, Gb, Ab, and Bb and six white keys: C, D, E, F, A, and B. This combination makes this scale - as well as the C Prometheus, C Prometheus Liszt, and C Prometheus Neapolitan - as great choices for composing or improvising music.
If we take a look a the key signature of the C Messiaen mode 7 inverse Scale we can find it has four flats and no sharps. Therefore, on sheet music you will find four accidentals on the score. The notes of this scale are: C, D, Eb, E, F, Gb, Ab, A, Bb, and B.