Orchestra macros work like C preprocessor macros, and replace the content of the macro in the orchestra before it is compiled. The opcodes one can use to create, call, or undefine orchestra macros are:

Orchestra macros can also be defined using the command line flag --omacro:.

More information and examples on the usage of orchestra macros can be found in the entry for #define.

These opcodes refer to orchestra macros, for score macros refer to Score Macros.