Translation music script from c# to js

hi, recently i've had a problem, how to make continuos the sogns between levels and avoiding to instantiate another music, the only solution that i've found was a c# script, it works, but i'm not able to edit that cause i don't know c#, only (a bit) javascript. So... can please someone translate that? thanks.

 using UnityEngine;
 using System.Collections;
 
 public class MyUnitySingleton : MonoBehaviour {
     
     private static MyUnitySingleton instance = null;
     public static MyUnitySingleton Instance {
         get { return instance; }
     }
     void Awake() {
         if (instance != null && instance != this) {
             Destroy(this.gameObject);
             return;
         } else {
             instance = this;
         }
         DontDestroyOnLoad(this.gameObject);
     }
     
 }