CrossFadeControl.ChangeMusicNextLevel C# (CSharp) Method

    private IEnumerator ChangeMusicNextLevel(AudioClip clip2, AudioClip clip3)
    {
        AudioSource fadeOut = null, fadeIn = null;
       //set audio 1 to new music
        fadeOut = audio3;
        fadeIn = audio1;
      
        //do fade
        float fTimeCounter = 0f;

        while (!(Mathf.Approximately(fTimeCounter, 1f)))
        {
            fTimeCounter = Mathf.Clamp01(fTimeCounter + Time.deltaTime);
            fadeOut.volume = 1f - fTimeCounter;
            fadeIn.volume = fTimeCounter;
            yield return new WaitForSeconds(0.02f);
        }
        audio2.clip = clip2;
        audio3.clip = clip3;
        StopCoroutine("ChangeMusicNextLevel");
    }