Notes: C, Db, Eb, E, F#, G, A, and Bb - Key: C - Category: Nonatonic or Ennatonic Scales
The C Messiaen mode 2 uses nine notes per octave. Because of this same reason it is a member of the so called Nonatonic or Ennatonic -scales that have Nine-note (or Nine-tone). On the piano keyboard, it is made up of four black keys: Db, Eb, F#, and Bb and four white keys: C, E, G, and A. 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 2 Scale we can find it has three flats and one sharps. Therefore, on sheet music you will find four accidentals on the score. The notes of this scale are: C, Db, Eb, E, F#, G, A, and Bb.