1570s, "map for the use of navigators," from Middle French charte "card, map," from Late Latin charta "paper, card, map" (see card (n.1)).
Charte is the original form of the French word in all senses, but after 14c. (perhaps by influence of Italian cognate carta), carte began to supplant it. English used both carte and card 15c.-17c. for "chart, map," and in 17c. chart could mean "playing card," but the words have gone their separate ways and chart has predominated since in the "map" sense. In the music score sense from 1957.