Hmmm, sounds like the mod did not enable. The music and text should change as soon as its enabled.
Did you unzip the whole rar to your mod folder? The mod folder is inside a main folder so you have to navigate to the second one and put that in your mod folder.
like this:
FS1MODv06
->FS1MODv06
->MAPS
Copy the second FS1MODv06 into your mod folder. hope that helps.
The files in the MAPS folder go into your Galaxy folder in your install directory.
I have found an issue with the freespaceTGWBIG map. The player2 (3rd) homeworld is not set as his homeworld. easy enough to fix.