I am creating an add-on which would ask the user to select music from a list and it would play it as background music. But previous posts show a sidebar with the user manually pressing the play button. I am wondering if there is a way to play it with Google Apps Script only. Also what would be helpful is if there was a volume property to set the volume?
My Code:

function onOpen(){
     DocumentApp.getUi()
          .createMenu("Background Music Add-On")
          .addItem("Select Music","music")
          .addItem("Set Volume","musicVol")
          .addToUi();
}

//music selection
function music(){

var musicName = DocumentApp.getUi()
     .prompt("Please select one of the music names:\n\nElevator Music,\nLeaf Rag.\nso on...")

     switch(musicName){
          case "Elevator":

               //code to play music Elevator

          break;

          //So On
     }
}