Having rediscovered the fact that Frescobaldi does not call convert-ly anymore. I went to the section 2.2 of the usage manual and popped the following into a windows 10 command prompt (with administrator privs)
C:\Program Files (x86)\LilyPond\usr\bin>forfiles /s /p "C:\users\peter\Lilypool\Music_Files\Bouffil" /M **.ly /c "cmd /c convert-ly.py -e @file" The result was 'convert-ly.py' is not recognized as an internal or external command, operable program or batch file. 'convert-ly.py' is not recognized as an internal or external command, operable program or batch file. 'convert-ly.py' is not recognized as an internal or external command, operable program or batch file. 'convert-ly.py' is not recognized as an internal or external command, operable program or batch file. 'convert-ly.py' is not recognized as an internal or external command, Etc etc for each .ly file in the folder I have cd'd to the Lilypond usr\bin folder so I don't think the three "s are needed here, but who knows Where did I go wrong? Regards Peter
