This is a difficult issue and one that I have experienced. The solution I am about to explain, I have not tested, though I will be using it soon to see.
The solution is to implement the music as if it is one long chain of switch changes. The "play music" event only ever happens once and it's at the beginning of the game. When new music is required, the switch is changed. The benefit is that, if the interactive music engine is already on switch A, and receives an event to go to switch A again, it does nothing.
I'm guessing that your trigger has a play action in the event. Can you change the event to use a switch instead?