Barrack-Unity/Assets/Scripts/Game/MusicManager.cs

using UnityEngine;
using System.Collections.Generic;

public class MusicManager : MonoBehaviour
{
    public AudioClip intro;

    public AudioClip loop;

    public AudioClip  outro;

    private AudioSource audioSource;

    private Queue<AudioClip> clipsQueue;

    // Start is called once before the first execution of Update after the MonoBehaviour is created
    void Start()
    {
        audioSource = GetComponent<AudioSource>();
        clipsQueue = new Queue<AudioClip>();

        // Intro is only played once, so we enqueue it first.
        clipsQueue.Enqueue(intro);
        ResetQueue();
    }

    // Update is called once per frame
    void FixedUpdate()
    {
	    if (audioSource.isPlaying == false)
        {
	        audioSource.clip = clipsQueue.Dequeue();
            audioSource.Play();

            if(clipsQueue.Count == 0)
            {
                ResetQueue();
            }
        }
    }

    private void ResetQueue()
    {
        clipsQueue.Enqueue(loop);
        clipsQueue.Enqueue(loop);
        clipsQueue.Enqueue(loop);
        clipsQueue.Enqueue(loop);
        clipsQueue.Enqueue(outro);
    }
}