ALWAYS put double quotes around tag attributes. ALL of them. Including numbers. In other words, <input type="hidden" name="id" value=23> is NOT right. It should be value="23". Got that? Ok.
When using associative arrays, get in the habit of using SINGLE quotes. PHP interprets that to mean "exactly what's in between the quotes." It's not absolutely necessary, but it's a good programming practice.
printf("<input type=\"hidden\" name=\"id\" value=\"%s\">
Artist <br><input type=\"text\" name=\"artist\" size=\"25\" maxlength=\"25\" value=\"%s\"><br>
Title <br><input type=\"text\" name=\"title\" size=\"25\" maxlength=\"25\" value=\"%s\"><br>
Picture <br><input type=\"text\" name=\"picture\" size=\"25\" maxlength=\"25\" value=\"%s\"><br>
Review <br><textarea name=\"review\" cols=\"30\" rows=\"5\">%s</textarea><br>
Label<br><input type=\"text\" name=\"label\" size=\"25\" maxlength=\"25\" value=\"%s\"><br>
Format <br><input type=\"text\" name=\"format\" size=\"25\" maxlength=\"25\" value=\"%s\"><br>
Price <br><input type=\"text\" name=\"price\" size=\"10\" maxlength=8 value=\"%s\"><br>
Rating <br><input type=\"text\" name=\"rating\" size=\"10\" maxlength=\"8\" value=\"%s\"><br>\n",
$myrow['id'],
$artist=$myrow['artist'],
$title=$myrow['title'],
$picture=$myrow['picture'],
$review=$myrow['review'],
$lable=$myrow['label'],
$format=$myrow['format'],
$price=$myrow['price'],
$rating=$myrow['rating']);
Of course, you could do this just as easily, which is a little easier to interpret:
<?php
$id=$myrow['id'];
$artist=$myrow['artist'];
$title=$myrow['title'];
$picture=$myrow['picture'];
$review=$myrow['review'];
$lable=$myrow['label'];
$format=$myrow['format'];
$price=$myrow['price'];
$rating=$myrow['rating']);
?>
echo <<<EOS
<input type="hidden" name="id" value="$id">
Artist <br><input type="text" name="artist" size="25" maxlength="25" value="$artist"><br>
Title <br><input type="text" name="title" size="25" maxlength="25" value="$title"><br>
Picture <br><input type="text" name="picture" size="25" maxlength="25" value="$picture"><br>
Review <br><textarea name="review" cols="30" rows="5">$review</textarea><br>
Label<br><input type="text" name="label" size="25" maxlength="25" value="$label"><br>
Format <br><input type="text" name="format" size="25" maxlength="25" value="$format"><br>
Price <br><input type="text" name="price" size="10" maxlength=8 value="$price"><br>
Rating <br><input type="text" name="rating" size="10" maxlength="8" value="$rating"><br>
EOS;