$result = mysql_query("SELECT * FROM users ORDER BY surname");

while($myrow = mysql_fetch_assoc($result))
{
$id = $myrow['id'];
$name = $myrow['name'];
$second_name = $myrow['second_name'];
$surname = $myrow['surname'];

$res = mysql_query("SELECT value FROM bunch WHERE id_user = '$id' ");
while ($mr = mysql_fetch_assoc($res))
{
$music = $mr['value'] . ', ';
}

echo "<table><tr>";
echo "<td> <b>Имя:</b> " . $surname . " " . $name . " " . $id . "</td></tr>";
echo "<tr><td> <b>Музыка:</b> " . $music . "</td></tr>";

}

$music = $mr['value'] . ', ';

$music = '';
while ($mr = mysql_fetch_assoc($res))
{
    $music .= $mr['value'] . ', ';
     // или так $music = $music . $mr['value'] . ', ';
}

SELECT users.*, bunch.value FROM users LEFT JOIN bunch 
ON users.id = bunch.id_user
ORDER BY users.surname

$music = '';
while ($mr = mysql_fetch_assoc($res))
{
    $music .= $mr['value'] . ', ';
     // или так $music = $music . $mr['value'] . ', ';
}
$music=substr($music,0,-2);//или mb_substr если кодировка UTF-8

$music = array();
while ($mr = mysql_fetch_assoc($res))
{
    $music[]= $mr['value'];
     // или так $music = $music . $mr['value'] . ', ';
}
$music=implode(', ',$music);

SELECT a.*,GROUP_CONCAT(b.`value`) as `values`
FROM `users` a
LEFT JOIN table2 b ON b.`id_user` = a.`id`
GROUP BY a.`id`

$res = mysql_query(... LEFT JOIN ...);
$firstid = 0;

while($myrow = mysql_fetch_assoc($res)) {
    if($firstid == 0) {
        $values = array($myrow['value']);
        echo '<table><tr>...'; // весь вывод нового пользователя до строчки с value
    } elseif($firstid != $myrow['id']) {
        echo implode(',',$values);
        $values = array();
        echo '</td></tr></table><'; // весь вывод нового пользователя после строчки value ПРОШЛОГО и до строчки с value!
    } else {
        $values[] = $myrow['value'];
    }
    echo $myrow['value'];
    $firstid = $myrow['id'];
}
if(count($values)) {
    echo implode(',',$values);
    $values = array();
    echo '</td></tr></table><'; // весь вывод нового пользователя после строчки value ПРОШЛОГО и до строчки с value!
}