Notes: C, E, F#, and A# - Key: C - Category: Pentatonic Scales
The C Messiaen truncated mode 6 inverse uses five notes per octave. Because of this same reason it is a member of the so called Pentatonic -scales that have Five-note (or Five-tone). On the piano keyboard, it is made up of two black keys: F#, and A# and two white keys: C, and E. 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 truncated mode 6 inverse Scale we can find it has no flats and two sharps. Therefore, on sheet music you will find two accidentals on the score. The notes of this scale are: C, E, F#, and A#.