late 14c., "draw up a line of battle," from Old French arengier "put in a row, put in battle order" (12c., Modern French arranger), from a- "to" (see ad-) + rangier "set in a row" (Modern French ranger), from rang "rank," from Frankish *hring or a similar Germanic source, from Proto-Germanic *hringaz "something curved, circle," from nasalized form of PIE root *sker- (2) "to turn, bend."
A rare word until the meaning generalized to "to place things in order" c. 1780-1800. Meaning "come to an agreement or understanding" is by 1786. Musical sense of "adapt for other instruments or voices" is from 1808. Related: Arranged; arranging. Arranged marriage attested from 1854.