From an essay by Jeffrey Tucker:
The people who make modern inventions are often celebrated for improving our lives. But what about those one thousand years ago who laid the very technological foundation of civilization as we know it? They too served the world, but with the primary purpose of contributing to the faith. I'm thinking here of those who solved the architectural problem to build the great cathedrals of the middle ages, and the scientists of the period who took the first steps toward modern medical knowledge.
Also we don't often consider the innovations in art that make all music possible. There is one person who stands out here: the late 10th and early 11th century Benedictine monk named Guido d'Arezzo (991/992–after 1033). He is credited with fantastic musical innovations that led to the creation of the modern system of notes and staffs, and also the organization of scales that allowed for teaching and writing music.
You can read the whole thing here.