[SCRIPT] Beta Mission Complete Sounds
Before you say anything else, I am aware of this mod.
What I'm suggesting/requesting is a mod that replaces the default mission complete sound with a blank/silent audio file, and a script that plays one of the six beta tunes at the end of certain missions - whichever seems more appropriate based on how important or how much impact the mission has on the story. Just like how GTA IV had different sounding tunes for more serious missions, or missions that ended on a dark note.
Probably would help to create a topic here or on the GTAForums to brainstorm with the community with what tune should play after what mission.