GGJ_2019/Assets/Scipts/SoundManager.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class SoundManager : MonoBehaviour {

    public AudioSource Startmusic;
    public AudioSource loopMusic;
    public AudioSource endMusic;

    public float gameLength = 120;
    AudioSource curMusic;
    public void Start()
    {
        Startmusic.Play();
        StartCoroutine(ChangeMusic(loopMusic, Startmusic.clip.length));
        StartCoroutine(ChangeMusic(loopMusic, gameLength - 10.0f));
    }

    private void Update()
    {
        
    }

    IEnumerator ChangeMusic(AudioSource music,  float musicTime)
    {
        while (musicTime > 0)
        {
            musicTime -= 1.0f * Time.deltaTime;
            yield return new WaitForEndOfFrame();
        }
        curMusic.Stop();
        curMusic = music;
        music.Play();
    }
}