Play music while game is starting

I’m creating a game in Unity (Targets: Mac/PC/Linux). I wish to play a 30 second looping track of music while the game loads.

I can code in C# and C++ outside of unity if that is needed. i use Visual studio 2017. The track is in MP3 format but I have the source so I can have it in other formats.

Thanks in advance.

This is impossible to do within unity.
If you don’t want to code outside of unity, you could try setting up a small scene that starts right after unity’s splash screen finish playing and does your own splash screen from there along with your music. This is the simplest workaround I could think of.

create a empty gamaobject and insert this script into it.
create script in c# and write codes

 using UnityEngine;
 using System.Collections;
 
 public class Carsound : MonoBehaviour {
 
     public AudioClip awoogah;
     public int carwait = 10;
     bool keepPlaying=true;
     
     void Start () {
         StartCoroutine(SoundOut());
     }
     
     IEnumerator SoundOut()
     {
         while (keepPlaying){
             audio.PlayOneShot(awoogah);  
             Debug.Log("ChOO-ChOO");
             yield return new WaitForSeconds(carwait);
         }
     }
 }