What was the significance of the tritone interval during the middle ages?

i believe it is a written question

It was particularly hard to sing correctly, and was used as a determining factor as to how good a group was musically

Explanation:

very interesting question. i'm a guy, so my vote hardly matters, but blue according to my wife is a purple with more blue than red.

the "brown"   is not mauve. that's the tough one. it has more brown the mauve in it. you almost need a color wheel to tell or a paint sample book. her gloves are a deeper purple.

i would also qualify this by saying you need say how good your monitor is. i'm working with a lap top so i couldn't swear by anything i've written is accurate. i had 3 women offer an opinion. they were not in agreement and they were not certain.

for posting. i'm more of a math type so i'm staying out of this but it was lots of fun.