Rhythm improvements

• The \time command now accepts a rational number in the numerator. The TimeSignature grob and \compound-meter markup function have new properties that control the style of fractional parts.

  

• The \time command now accepts a rational number in the denominator to support time signatures with a beat longer than a whole note.

  {
    \override Timing.TimeSignature.denominator-style = #'note
    \time #'(4 . 1/2)
    e'\breve f' g' a'
  }
  

  

• The TimeSignature grob and \compound-meter markup function now support number-over-note time signatures via denominator-style and related properties.

  {
    \override Timing.TimeSignature.style = #'numbered
    \override Timing.TimeSignature.denominator-style = #'note
    \once \override Timing.TimeSignature.fraction = #'(2 . 8/3)
    \time 6/8
    r4. g'8 8 8
  }
  

  

• The TimeSignature.fraction property now accepts a number-pair? value, which is more general than the previous fraction?. This makes certain tricks possible without overriding the stencil property.

  {
    \once \override Timing.TimeSignature.fraction = #'(-1 . 12)
    R1
  }
  

  

• \slashedGrace now prints slashed beams.

  {
    \slashedGrace { d'16 e' d' } c'1
    \slashedGrace { d16 e'' d' } c'1
  }
  

  

  Use beam::slashed-stencil to slash arbitrary beams. Set details.slash-side to RIGHT to print the slash at the right side of the beam.

  {
    \override Beam.stencil = #beam::slashed-stencil
    \cadenzaOn
    c'16^[ a' c'']
    c''^[ a' c']
    c'_[ a' c'']
    c''_[ a' c']
    \override Beam.details.slash-side = #RIGHT
    c'16^[ a' c'']
    c''^[ a' c']
    c'_[ a' c'']
    c''_[ a' c']
  }
  

  

  Use the over-beam-height, slash-slope, slash-side, slash-stem-fraction, slash-thickness, and slash-X-positions subproperties of the details property to customize the appearance of the slash.

• It is now possible to right-align different types of bar lines.

  \new StaffGroup
    <<
      \new Staff { \textMark "default" b1 }
      \new Staff { b1 \section }
    >>
  
  \new StaffGroup
    <<
      \new Staff
        { \textMark "right-aligned" b1 }
      \new Staff
        { b1
          \override StaffGroup.BarLine.right-justified = ##t
          \section }
    >>
  

  

• Bar checks (|) now implicitly create contexts. The developers deem this unlikely to impact real-world scores. Please report a bug if you find a problem without an obvious workaround.
• The new span-all-note-heads option may be used to make tuplet brackets span all note heads (not just the stems) as recommended by Gould and Ross.

  

• Automatic beam subdivision has been reworked. Previously, many imperfections could be found in the results of automatic subdivision of many complex beaming patterns due to overreliance of the value of beatBase. Now, LilyPond can correctly subdivide most beaming patterns and no longer uses the value of beatBase to limit beam subdivision. Simply setting subdivideBeams to #t now automatically subdivides all intervals by default. Three new properties have been introduced to tune automatic beam subdivision: beamMinimumSubdivision, beamMaximumSubdivision and respectIncompleteBeams. beamMinimumSubdivision limits subdivision intervals the same way as how beatBase previously did (reducing frequency of subdivided beams). beamMaximumSubdivision limits the number of beamlets removed at subdivisions in general. respectIncompleteBeams limits the number of beamlets at subdivisions where the remaining length would not complete the metric value of the subdivision. Setting beamMinimumSubdivision to the value of beatBase at all times, even when beatBase implicitly changes, preserves old behavior.
• New ‘stacked’ flag glyphs are available. All flag elements of a flag glyph have the same width but are vertically more compact.

  Use \flagStyleStacked to access them; with \flagStyleDefault you can switch back to the standard flag style.

  

• The TimeSignature style 'single-digit has been renamed to 'single-number.