From MusiCAD

GhostScript is a free implementation of the PostScript language which enables MusiCAD to save music as PDF, JPG and PNG. By default all printing is performed using GhostScript. The GhostScript dialog [Options|Preferences|GhostScript] makes it possible to fine-tune GhostScript operation and even replace GhostScript with another postscript interpreter, as is required when using GPL-licensed software (GhostScript) bundled with non GPL software (MusiCAD)

[GhostScript (GS)]
It is possible to print without GhostScript: just uncheck GS.
The filename of the actual GhostScript executable: gs550.exe, if version 9.50 is installed gswin64.exe would be used.
Command line options to be presented to GhostScript:
-q quiet-mode
-dBATCH non-interactive
-dNOPAUSE don't pause between pages
[GS Device]
Printer driver to be used, usually mswinpr2
[GS directory]
Directory where the GhostScript files are located, version 5.50 uses a sub directory of the main installation directory: C:\Program Files (x86)\Musys Software\MusiCAD 4.2\gs The optional 9.50 version would be installed in C:\Program Files\gs\gs9.50\bin
[GS destination]
Full filename for the temporary postscript file generated