2.5 Manual conversions

In theory, a program like convert-ly could handle any syntax change. After all, a computer program interprets the old version and the new version, so another computer program can translate one file into another1.

However, the LilyPond project has limited resources: not all conversions are performed automatically. Below is a list of known problems.

 Doesn't always convert figured bass correctly, specifically things like {<
>}.  Mats' comment on working around this:
   To be able to run convert-ly
   on it, I first replaced all occurrences of '{<' to some dummy like '{#'
   and similarly I replaced '>}' with '&}'.  After the conversion, I could
   then change back from '{ #' to '{ <' and from '& }' to '> }'.
 Doesn't convert all text markup correctly.  In the old markup syntax,
 it was possible to group a number of markup commands together within
parentheses, e.g.
   -#'((bold italic) "string")
   This will incorrectly be converted into
   -\markup{{\bold italic} "string"}
   instead of the correct
   -\markup{\bold \italic "string"}
 Doesn't handle \partCombine
 Doesn't do \addlyrics => \lyricsto, this breaks some scores with multiple
 \magnify isn't changed to \fontsize.
    - \magnify #m => \fontsize #f, where f = 6ln(m)/ln(2)
 remove-tag isn't changed.
    - \applyMusic #(remove-tag '. . .) => \keepWithTag #'. . .
 first-page-number isn't changed.
    - first-page-number no => print-first-page-number = ##f
 Line breaks in header strings aren't converted.
    - \\\\  as line break in \header strings => \markup \center-align <
      "First Line" "Second Line" >
 Crescendo and decrescendo terminators aren't converted.
    - \rced => \!
    - \rc => \!
 \turnOff (used in \set Staff.VoltaBracket = \turnOff) is not properly
 \markup{ \center-align <{ ... }> } should be converted to:
 \markup{ \center-align {\line { ... }} }
 but now, \line is missing.
 Special LaTeX characters such as $~$ in text are not converted to UTF8.
 \score{} must now begin with a music expression.  Anything else
 (particularly \header{}) must come after the music.


[1] At least, this is possible in any LilyPond file which does not contain scheme. If there is scheme in the file, then the LilyPond file contains a Turing-complete language, and we run into problems with the famous “Halting Problem” in computer science.

LilyPond — Usage v2.24.3 (stable-branch).