(1) Any musical score.
(2) A special type of score, typically used by jazz musicians. Only the melody line, words (if any) and chord symbols are given. Clef, key signature and meter are given once only, at the beginning. The standards of musical notation and calligraphy are low. Charts are not written with anywhere near the precision of orchestral scores. (Much like the Pirate’s Code, they are more guidelines than actual rules.) The idea being to encourage improvisation and the musician’s unique interpretation. Every jazz musician has his/her own book of miscellaneous charts.