Controlling the appearance of tremolo slashes

Using various properties of the StemTremolo grob it is possible to control the appearance of tremolo slashes.

• Property slope sets the slope for tremolo slashes.
• Property shape determines whether tremolo slashes look like rectangles (value rectangle) or like very small beams (value beam-like).
• Property style sets both the slope and the shape depending on whether the note has flags, beams, or only a plain stem. This is in contrast to the previous two properties, which change the slope and shape unconditionally. There are two styles defined.
  • default: slashes for down-stem flags are longer and more sloped than slashes for up-stem flags; slashes on beamed notes have a rectangular shape and are parallel to the beam.
  • constant: all slashes are beam-like and have the same slope except for down-stem flags.

\version "2.24"

music = {
  a''4:32 a':
  e''8: \noBeam e':
  a'':[ a':]
  f':[ g':]
  d':[ d':]
}

\new Staff {
  <>^\markup "default"
  \music
}

\new Staff {
  <>^\markup \typewriter "style = #'constant"
  \override StemTremolo.style = #'constant
  \music
}

\new Staff {
  <>^\markup \typewriter "shape = #'rectangle"
  \override StemTremolo.shape = #'rectangle
  \music
}

\new Staff {
  <>^\markup \typewriter "shape = #'beam-like"
  \override StemTremolo.shape = #'beam-like
  \music
}

\new Staff {
  <>^\markup \typewriter "slope = -0.2"
  \override StemTremolo.slope = -0.2
  \music
}