Progression of Eight Notes on a Musical Scale
This page is the CodyCross answer for the clue below from Train Travel, Group 709, Puzzle 4 (From Russia With Love).
Question is: Progression of Eight Notes on a Musical Scale
and the answer is: OCTAVE
Word Meaning:
OCTAVE — (music) An interval of twelve semitones spanning eight degrees of the diatonic scale, representing a doubling or halving in pitch frequency.
Definitions from Wiktionary.