sound.Play() will not work

i am very new to coding so I'm not the greatest person to do. i found a bug with my game that my deathSong.Play() would not work (near the bottom). some reason all the other things in Die() work perfectly fine including the death menu its just the song wont play even though i have carried the Audio Source into the correct place and everything, its not muted or disabled, it just doesnt play. is there anyone that can tell me whats going on in my 2d game?

 public class Player_move : MonoBehaviour
 {
     public bool cantMove = false;
     public bool cutSceneActivated = false;
     public int playerHealth;
     public int playerSpeed = 1;
     public float moveX;
     public int jumpPower = 125;
     public bool isGrounded;
     private int maxHealth = 5;
     public DeathMenu deathMenu;
     private float startTime;
     public Score score;
     public bool hit = false;
     public AudioSource hurtSound;
     public AudioSource mainTheme;
     public AudioSource deathSong;
 
     public float knockBackAmount = 50;
 
 
     void Start()
     {
         playerHealth = maxHealth;
         //startTime = Time.time;
     }
 
     void Update ()
     {
 
         if (hit == true)
         {
             hurtSound.Play();
             hit = false;
         }
         else if (playerHealth <= 0)
         {
             Die();
         }
         else if (!cantMove)
         {
             playerMove();
 
             if (moveX > 0.0f && moveX != 1.0f)
             {
                 GetComponent<Animator>().SetBool("IsWalking", true);
             }
             else if (moveX < 0.0f && moveX != -1.0f)
             {
                 GetComponent<Animator>().SetBool("IsWalking", true);
             }
             else if (moveX == 1.0f)
             {
                 GetComponent<Animator>().SetBool("IsRunning", true);
             }
             else if (moveX == -1.0f)
             {
                 GetComponent<Animator>().SetBool("IsRunning", true);
             }
             else
             {
                 GetComponent<Animator>().SetBool("IsRunning", false);
                 GetComponent<Animator>().SetBool("IsWalking", false);
             }
         }
 
     }
     void jump()
     {
         GetComponent<Rigidbody2D>().AddForce(Vector2.up * jumpPower);
         isGrounded = false;
     }
 
     void OnTriggerEnter2D(Collider2D collision)
     {
         if (collision.gameObject.name == "DeathZone")
         {
             Die();
         }
     }
     public void cutScene()
     {
         if (cutSceneActivated)
         {
             cantMove = true;
         }
         else if(!cutSceneActivated)
         {
             cantMove = false;
         }
     }
     void playerMove()
     {
         moveX = Input.GetAxis("Horizontal");
         if (Input.GetButtonDown("Jump") && isGrounded)
         {
             jump();
         }
         if (moveX < 0.0f)
         {
             GetComponent<SpriteRenderer>().flipX = true;
         }
         else if (moveX > 0.0f)
         {
             GetComponent<SpriteRenderer>().flipX = false;
         }
         gameObject.GetComponent<Rigidbody2D>().velocity = new Vector2(moveX * playerSpeed, gameObject.GetComponent<Rigidbody2D>().velocity.y);
         
     }
        // fix this
     void Die()
     {
         mainTheme.enabled = false;
         hurtSound.enabled = false;
         //this next line of code needs to be fixed
         deathSong.Play();
         cantMove = true;
         moveX = 0;
         deathMenu.ToggleEndMenu();
     }
 }