Lead sheet
Score with melody and chord symbols used as a playing basis in jazz and pop.
What it means
A lead sheet notates only the essentials of a piece: the melody line, lyrics where relevant, and chord symbols placed above the staff. How the accompaniment is realized, including voicing, rhythm and instrumentation, is left open and decided by the performers.
This economical notation is the standard working format in jazz and much of popular music, where pieces are often interpreted differently depending on the line-up and the moment.
In the notation
Chord symbols (e.g. Cmaj7, G7, Dm9) appear above the staff, indicating harmony and typical extensions. Formal sections such as chorus or bridge are often marked with letters (A, B) or repeat signs.
Musical use
Lead sheets underpin the jazz standard repertoire, collected for instance in fake books such as the Real Book, and also serve as a quick reference at band rehearsals or for musical theatre pit bands. A lead sheet should be distinguished from a fully written-out score, which fixes voicing, rhythm and instrumentation, and from a plain chord chart that omits the notated melody.
Performance practice
When playing from a lead sheet, build your own accompaniment figure from the chord symbols and follow the notated melody and form in ensemble playing, rather than waiting for fully written-out individual parts.