A chord chart (or chart) is a form of musical notation that in addition to writing out non-embellished melody, describes harmonic and rhythmic information. It is the most common form of notation used by professional session musicians playing jazz or popular music. It is intended primarily for a rhythm section (usually consisting of piano, guitar, drums and bass). In these genres the musicians are expected to be able to improvise the actual notes used to represent the chord and the appropriate ornamentation or counter melody.

The harmony is given as a series of chord symbols above a traditional musical staff. The rhythmic information can be very specific and written using a form of traditional notation, sometimes called rhythmic notation, or it can be completely unspecified using slash notation, allowing the musician to fill the bar any way he sees fit (called "comping"). In Nashville notation the key is left unspecified by substituting numbers for chord names.

Chord charts are similar to the figured bass ("basso continuo")^{[citation needed]} system used as early as the beginning of the seventeenth century to allow the continuo ("rhythm section") keyboard to improvise right-hand chords over a written bass line played with the left hand. Since it uses key-relative "figures" rather than absolute chord-names, figured bass most closely resembles Nashville notation (described below).^{[citation needed]}