+The lines of a staff belong to the @code{StaffSymbol} grob (including
+ledger lines) can be modified using @code{StaffSymbol} properties, but
+these modifications must be made before the staff is (re)started.
+
+The number of staff lines can be altered,
+
+@lilypond[verbatim,quote,relative=2]
+f4 d \stopStaff
+\override Staff.StaffSymbol #'line-count = #2
+\startStaff g, e |
+
+f'4 d \stopStaff
+\revert Staff.StaffSymbol #'line-count
+\startStaff g, e |
+@end lilypond
+
+The position of each the staff lines can also be altered. The values
+used are @emph{half} staff line spaces and the new position is relative
+to the normal center line. A single staff line is printed for every
+value entered so that the number of staff lines, as well as their
+position in the staff, can be changed with a single override.
+
+@lilypond[verbatim,quote,relative=2]
+f4 d \stopStaff
+\override Staff.StaffSymbol #'line-positions = #'(1 3 5 -1 -3)
+\startStaff g, e |
+f'4 d \stopStaff
+\override Staff.StaffSymbol #'line-positions = #'(8 6.5 -6 -8 -0.5)
+\startStaff g, e
+@end lilypond
+
+The clef position and the position of middle C may need to be adjusted
+accordingly to fit the new lines. See @ref{Clef}.
+
+Staff line thickness can be altered. Ledger lines and note stems, by
+default, are also affected.
+
+@lilypond[verbatim,quote,relative=2]