Yes, you could connect a button to both the Maestro and the MP3 Trigger and have your Maestro script and audio track start at the same time.
You can find information about connecting a button the Maestro in the “Attaching Servos and Peripherals” section of the Maestro user’s guide. To start your servo movements from a button press you will have to write some code at the beginning of your script. I recommend looking through the “Example Scripts” section of the Maestro user’s guide as well so you can get an idea of how handling button presses would work, but you can also find some sample code to start your script with the push of a button in my post here.
If you have additional questions about using a button with the Maestro, I suggest creating a new topic of your own, since this is getting away from the original topic of this thread.
Brandon