Ledger line
A ledger line or leger line is used in Western musical notation to notate pitches above or below the lines and spaces of the regular musical staff. A line slightly longer than the note head is drawn parallel to the staff, above or below, spaced at the same distance as the lines within the staff (see Figure 1).
The origin of the word is uncertain, but may have been borrowed attributively from the term used to describe a horizontal timber in a scaffolding, lying parallel to the face of the building and supporting the putlogs. There is no basis to support the often-found claim that the word originates from the French léger, meaning "light" or "slight" (OED 2005).
Although ledger lines are found occasionally in manuscripts of plainchant and early polyphony, it was only in the early 16th century in keyboard music that their use became at all extensive (Anon. 2001). Even then printers had an aversion to ledger lines which caused difficulties in setting type, wasting space on the page and causing a messy appearance. Vocal music employed a variety of different clefs to keep the range of the part on the staff as much as possible; in keyboard notation a common way of avoiding ledger lines was the use of "open score" on four staves with different clefs (Godwin 1974, 16–17).
Except for woodwind players, who prefer ledger lines to all'8va notation because they associate fingerings with staff positions (Shatzkin 1993, 48), notes that use more than two or three ledger lines make the music illegible. In order to prevent this issue, the composer would usually switch clefs or use the 8va notation. Some transposing instruments, such as the piccolo, double bass, guitar, and the tenor voice, transpose at the octave to avoid ledger lines.
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