upload twilio recording to soundcloud

twilioSoundcloud.php

<?php
// download the recording to the local machine
file_put_contents("recording.wav", file_get_contents($_POST['RecordingUrl']));

// setup the track info to send to soundcloud
$track = array(    
    'track[asset_data]' => '@recording.wav' // adding @ adds the contents to $_FILES
);

// upload the sound using the soundcloud php sdk
$response = $soundcloud->post('tracks', $track);