The advent of the printing press in the Renaissance allowed the wide distribution of printed music. This allowed composers to sell their work more widely and obtain a better living. Important Renaissance composers and arrangers of music include Josquin Des Prez and Tielman Susato.
(This is the very beginnings of the article ... I'm sure that Cormac or someone a lot more knowledgeable than I could write several pages here. As a side note I've never heard of Johann Fux -- what did he do?)