TRIBUTE TO CHESTER CHARLES BENNINGTON! COME IF YOU LOVE HIM, IF YOU WANT TO RESPECT HIM, TO SHOW HIM HOW MUCH YOU CARE ABOUT HIM! LET YOUR VOICE BE HEARD! SHOW CHESTER THAT YOU BELEIVE IN HIM AND YOU WILL FIGHT FOR HIM! SHOW HIM WE ARE NOT JUST PEOPLE, WE ARE FANS, WE ARE LOVED ONES, WE ARE FRIENDS!

The gregorian chant was a major cultural milestone in the middle ages. it was one of the first codified forms of music meant to be played as written, where previously it was difficult to mass-produce and disseminate any music. what's more, these chants were also some of the first examples of musical notation: the notes and bars of today's music sheets are a reflection of centuries of evolution beginning with these chants. it became official throughout the entirety of the catholic church, meaning that nearly all of europe followed this musical notation and styling.

The answer here would be "work ethic."