if I have an audio(html5) tag like example bellow contains an audio(not empty)

how can I upload the audio content to my server using ajax. the problem is what the attribute or value of audio tag should I send by ajax to action in the controller. . html part:

<audio id="audiotag" src="http://www.sololearn.com/uploads/audio.mp3" controls>
    Audio element not supported by your browser
</audio>

ajax:

$.ajax({
        type: 'POST',
        data: { 'recording': $('#audiotag').val() },
        url: '@Url.Action("UploadAudio", "Pages")',
        success: function (data) {
          alert('s');
        }
     });

action in controller:

public async Task<IActionResult> UploadAudio(IFormFile recording)
    {
        string audio = await UserFile.UploadeNewFileAsync("", recording, 
       _environment.WebRootPath, Properties.Resources.Courses);

        return Ok();
    }