trying to send data to a server and receive a response then proceed to display it

I am trying to send data to a server and receive a response then proceed to display it. But I keep getting The following error: Uncaught TypeError: Cannot use 'in' operator to search for '2448' in

My PHP CODE:

<?php

header('Access-Control-Allow-Origin: *'); include ('connection.php');

$album = $_POST["album"];

$sql = " SELECT album.id as album, album.name as album_name, track.name as title, track.number as track_number, track.lyric as lyrics, track.details as track_url, artist.profile as artist, image.url as image

    FROM album 
    INNER JOIN track ON
    album.id = track.album_id
    INNER JOIN image ON
    image.details = album.id
    INNER JOIN artist ON
    artist.id = album.artist_id

    WHERE album.id='".$album."' ORDER BY track.number ASC";

$result = mysql_query($sql) or die ("Query error: " . mysql_error());

$records = array();

while($row = mysql_fetch_assoc($result)) {
$records[] = $row;
}


mysql_close($con);

echo $_POST['jsoncallback'] . '(' . json_encode($records) . ');';

?>

MY AJAX CALL:

function load_album_tracks(album_id){
    document.getElementById("track_titles").innerHTML = "";
    alert(album_id);
$.ajax ({
    type:'POST',
    data:  {album:album_id},
    dataType: 'jsonp',
    jsonp: 'jsoncallback',
    url: 'http://ift.tt/1LWaXe6',
    success: function(data){
        console.log(data);
    $.each(data, function(i,item){ 
    var track = /** DISPLAY RESULTS **/;    
    document.getElementById("track_titles").innerHTML += track;
    });

},
 error: function(data){
            alert("Couldn't Load Tracks");  
            }
        });

}