Csound Orchestra and Score text can be passed directly into a generated CSD by using the Global Orchestra and Global Score windows.
Anything here will be inserted into the <CsOrchestra> section of the .CSD file before anything generated by the Orchestra. Things like global variables, macros, or GUI instrument definitions may go here.
Anything here will be inserted into <CsScore> section of the .CSD file before anything generated by the score timeline. the global score's processing is done outside of the score timelines, so any notes put here are not factored into values calculated from the timeline, like total duration, nor are any notes in the global score section translated like the timeline is when a different start time is used other than 0.0. for instance, if you use 2.0 as a start time, a note in the score timeline at 2.0 will be translated to start at 0.0, while a note with a start time of 2.0 in the global score section is not affected and will start at time 2.0.
There are also certain variables made available from Blue (Blue variables) that are useful for specific purposes. One of them is <TOTAL_DUR>. An example of its use is:
i20 0 [<TOTAL_DUR> + 10] .95 1 1000
The note given above is for a global effect(a global reverb unit). This note will always start at time zero regardless of when the score starts, and will always last as long as the duration of the generated score from the timeline plus 10 seconds. Because Blue variables are a text swap, the above use of the bracket notation that Csound uses was necessary. For a score with a 20 second duration, the above note would have been generated as:
i20 0 [20 + 10] .95 1 1000
Because of the Blue variable used, the note will correclty play regardless of when the score starts. If the the Blue variable was note used and was put as a note in the Score timeline, the reverb may not run.
When Blue variables were created, Blue did not have a Mixer system implemented. The above system continues to function, the practice of using the Mixer is highly recommended. This feature is left in for legacy projects.