Hello,
Have your read the General Advice For Getting Help? You should not be mentioning playing music at all at this point, unless you already have it working without the music. Other than that, it sounds like you are asking us to debug your code and configuration without giving us any information about either one! (Are you even writing code? What is “VSA”?)
I recommend that you first verify that you can move servos with the Maestro Control Center, make sure you have configured the Maestro for serial communication in Dual-Port Mode, explain how you picked COM4, try our Serial Transmitter, then simplify your code as much as possible and see if it works.
-Paul