Music management app, mashing data from various APIs
Please add the following method do your code and print the runtime of every section of your code. As indicated by my comment I guess the foreach->simplexml_load_file("...") might take a while.

//PHP &lt;5.0.0
function microtime_float()
{
    list($usec, $sec) = explode(" ", microtime());
    return ((float)$usec + (float)$sec);
}

$start=microtime_float();
//...
echo microtime_float()-$start;

//PHP&gt;=5.0.0
$start=microtime(true);
//...
echo microtime(true)-$start;