chart
A written arrangement or lead sheet used by jazz and studio musicians.
In Depth
In jazz, a chart typically means a lead sheet showing melody, chord symbols, and basic form. In studio and big band contexts, a chart is a full arrangement with parts for each instrument. Session musicians pride themselves on being able to sight-read charts perfectly on the first take. Nashville charts use a number system instead of chord letters, allowing instant transposition to any key. The quality of charts directly affects rehearsal efficiency.
Studio musicians in Los Angeles and Nashville can record three or four complete songs per three-hour session, sight-reading charts they have never seen before.