What Greek mathematician came up with the idea of the octave and first focused on the pleasing sounds that some notes make together

Pythagoras

Explanation:

A tripling of frequency gives a perfect fifth one octave higher. They didn't know this in terms of frequencies, but in terms of lengths of vibrating strings. Pythagoras, who experimented with a monochord, noticed that subdividing a vibrating string into rational proportions produces consonant sounds.

i came across this and i found it funny that when you're bored you play hangman on so im going to guess a : )

melody. a series of single tones which add up to a recognizable whole is called a what kind of layers of sound are heard melody or harmony. how many layers