Why did people suspect that the Minoan and the Mycenaean civilizations have existed even before archaeologists discovered their ruins.

There were mentions of them in works of Western Civilization. For example, Mycenaens were described in the Iliad by Homer repeatedly. And the Minoan people were mentioned in the Bible.

a chromatic scale uses the twelve tones of the octave, while a regular scale only uses eight, or seven different notes (as the first note is played twice)