Change the volume of the music menu

Hello, first of all sorry for my bad english … Now, I’m recreating the Slender by a youtuber and the person who is creating not put music on the menu, I decided to get but when I go to Options and change the volume of the game nothing happens in the music menu, just change the rest sound. …: s Can someone help me? Would be internally grateful …

My problem is that I added a song to my menu, but when I go to the game options and methodological higher or lower the music that added nothing happened, only resulted in sounds that I had inserted into the game. Get it? : s

using UnityEngine;
using System.Collections;

public enum Menus{
MainMenu,
Options,
Credits
}

public class MainMenuController : MonoBehaviour {

public Menus currentMenu = Menus.MainMenu;
private float currentVolume = 1;
private float currentSensibility = 10;
public float maxSensibility = 16;
public float minSensibility = 3;
public string textCredits;

public GUISkin guiSkinToUse;

public Texture logoGame;

// Use this for initialization
void Start () {
	if(PlayerPrefs.HasKey("CurrentVolume")){
		currentVolume = PlayerPrefs.GetFloat("CurrentVolume");
	}
	else{
		PlayerPrefs.SetFloat("CurrentVolume", currentVolume);
	}

	if(PlayerPrefs.HasKey("CurrentSensibility")){
		currentSensibility = PlayerPrefs.GetFloat("CurrentSensibility");
	}
	else{
		PlayerPrefs.SetFloat("CurrentSensibility", currentSensibility);
	}
	
}

// Update is called once per frame
void Update () {	

}

void OnGUI(){
	GUI.skin = guiSkinToUse;
	MenusGame();
}

void MenusGame(){

	Vector2 sizeLogo = GetAbsolutePixels(new Vector2(60, 30));

	GUI.DrawTexture(new Rect (Screen.width/2-sizeLogo.x/2, 60, sizeLogo.x, sizeLogo.y), logoGame);

	switch(currentMenu){
	case Menus.MainMenu:{
		//
		GUILayout.BeginArea(new Rect(Screen.width/2-70, 400, 150, Screen.height));
		if(GUILayout.Button("Play")) Application.LoadLevel("GamePlay");
		if(GUILayout.Button("Options")) currentMenu = Menus.Options;
		if(GUILayout.Button("Credits")) currentMenu = Menus.Credits;
		GUILayout.Space (10);
		if(GUILayout.Button("Exit")) Application.Quit();
		GUILayout.EndArea();
	}break;
	case Menus.Options:{
		//
		GUILayout.BeginArea(new Rect(Screen.width/2-70, 400, 150, Screen.height));
		GUILayout.Label("Options");
		GUILayout.Space(3);
		GUILayout.Label("Volume");
		currentVolume = GUILayout.HorizontalSlider(currentVolume, 0, 1);
		GUILayout.Label("Mouse Sensibility");
		currentSensibility = GUILayout.HorizontalSlider(currentSensibility, minSensibility, maxSensibility);
		if(GUILayout.Button("Save")) SavePreferens();
		GUILayout.Space(10);
		if(GUILayout.Button("Back")) currentMenu = Menus.MainMenu;
		GUILayout.EndArea();
	}break;
	case Menus.Credits:{
		//
		GUILayout.BeginArea(new Rect(Screen.width/2-70, 400, 150, Screen.height));
		GUILayout.TextArea(textCredits);
		GUILayout.Space(10);
		if(GUILayout.Button("Back")) currentMenu = Menus.MainMenu;
		GUILayout.EndArea();
	}break;
	}
}

void SavePreferens(){
	PlayerPrefs.SetFloat("CurrentVolume", currentVolume);
	PlayerPrefs.SetFloat("CurrentSensibility", currentSensibility);
}

Vector2 GetAbsolutePixels(Vector2 pixels){
	Vector2 pixelsAbsolute = Vector2.zero;
	pixelsAbsolute.x = pixels.x*Screen.width/100;
	pixelsAbsolute.y = pixels.y*Screen.width/100;

	return pixelsAbsolute;
}

}