Here are some macros which can make a single staff appear
as though its right side has been torn off. Two styles are
available: the first "erases" the ends of individual staff-
lines to different lengths; the second draws a zigzag line
and erases everything to its right. Furthermore, the first
type is capable of producing tear-patterns at random. Both
work by temporarily modifying the BarLine stencil.

STYLE 1 PREFERENCES:

  tearWidth  ...  default is 1
    horizontal distance (measured in staff-spaces) between 
    the end-points of the shortest and longest staff-lines.

  tearXext  ...  default is '(0 . 0)
    X-extent of the BarLine stencil, NOT including its width.
    Can be used as "padding" around the stencil, if needed.
  
STYLE 2 PREFERENCES:

  zigzagDefaultYext  ...  default is '(-4 . 4)
    Y-extent of the zigzag BarLine stencil (measured in 
    staff-spaces).

  zigzagDefaultSerrationCount  ...  default is 5
    Number of "teeth" or "notches" on the zigzag line.

  zigzagTearLineWidth  ...  default is 0.1
    Width of the zigzag line itself.

  zigzagTearAngle  ...  default is 90
    Angle (measured in degrees) of kinks in the zigzag line.

  zigzagTearXext  ...  default is '(0 . 0)
    X-extent of the zigzag BarLine stencil, NOT including its
    width. Can be used as "padding" around the stencil, if needed.

USAGE:

  see the \score { } block at the end of the file.