Source : Webster's Revised Unabridged Dictionary (1913)

Arranger \Ar*ran"ger\, n.
   One who arranges. --Burke.

Source : WordNet®

arranger
     n 1: a person who brings order and organization to an enterprise
          [syn: {organizer}, {organiser}]
     2: a musician who adapts a composition for particular voices or
        instruments or for another style of performance [syn: {adapter},
         {transcriber}]