Change Music When GameObject is Grabbed?

Hello again for the 1000th time awesome people of Unity Answers, I have a question as always. I managed to get my music to changed to a different track when I grab a certain gameobject, however when I grab the gameobject again it changes back to the first music track. My question is, how can I stop it from changing back to the first track, and instead just restart the second track over? Example: Track 1 plays, grabs gameobject, Track 2 plays for 10 seconds, grabs the gameobject again, Track 2 replays starting at 0 seconds(the beginning). Here's my music and how it changes so far:

 public float defaultSpeed = 5f;
 public float maxSpeed = 10f;

 public AudioClip[] songs;
 AudioSource audio;

 public float coeffSpeedUp = 5f;
 public float coeffSpeedUpTime = 5f;
 
 // Use this for initialization
     void Start ()
     {
 
         audio = GetComponent<AudioSource> ();
 
         audio.clip = songs [0];
         audio.Play ();
 }
 
 public void SpeedUp()
     {
         Debug.Log( "SpeedUp()" );
         // Speed up the player
         speed = defaultSpeed * coeffSpeedUp;
 
         audio.Stop (); //pauses the Track 1
         audio.clip = songs [1]; //gets the Track 2
         audio.Play (); // plays Track 2
         
         CancelInvoke ("EndSpeedUp"); // in case the method has already been invoked
         Invoke ("EndSpeedUp", coeffSpeedUpTime = 5 );
 
 }
 
 void EndSpeedUp()
     {
         //Changes how fast the player goes
         Debug.Log ("ending");
         speed = defaultSpeed; // back to normal
         renderer.material.color = Color.white;
     
         audio.Stop (); //stops the Track 2
         audio.clip = songs [0]; //Gets the Track 1
         audio.Play (); //Plays Track 1
     }
 }

I call the function SpeedUp() by using this script(note that this script is the gameobject I grab): http://pastebin.com/8JxXvDan As for the EndSpeedUp() function, it's called 5 seconds after the SpeedUp function.

I know inefficient code, don't judge me. Anyways thanks for reading and your time.