I am importing some scores of unmetered music into Lilypond via MusicXML, and naturally Lilypond is producing far superior results to Finale. To make the files appear as they do in other programs, I am trying to work out how to add support for manual measure durations in musicxml2ly.
This allows the composer to insert any number of beats into a particular measure regardless of the time signature, using this markup as a child of <measure>:
Here is the MusicXML documentation, with an example:
It appears to me that adding \cadenzaOn and \cadenzaOff before and after the relevant measures is the simplest approach, but I would appreciate knowing about other use cases that might suggest another approach:
I have not yet determined the best way of modifying the code to achieve this, having only written basic Python scripts in the past, but am hoping to work it out. If anyone else is able to help, I am happy to provide any number of example files.