I think that when the event is not active that the music should be kinda low and normal.
But when the event starts and the sky turns dark...you should here some music that gets you both scared and pumped up. Not that this is a good song for it but I remember when I heard the score from Starfox for the first time I was both pumped and in awh.
Well the links don't work for me, it says no hot linking. But yes, some type of music would be good for the zone/event. As a place holder maybe they could use this piece from the STO soundtrack: Generic Battle 4
Just got done doing the invasion on medium, still hold strong in my belief that an alert at the beginning of the event, and music would help make it awesome. For some reason my ported VA does not get the system messages that fly by on tribble during the event. Also my ported VA cannot access any costumes after the 4th slot. I bought several slots but I can only access the first 4 on tribble.