I am developing an android app that download songs(so type of data is blob) from db.
I have the following download image code example:
$id = $_GET['id'];
$sql = "select * from images where id = '$id'";
$r = mysqli_query($con,$sql);
$result = mysqli_fetch_array($r);
You'll want to send the following header for a .mp3 file:
Refer to https://www.sitepoint.com/web-foundations/mime-types-complete-list/ for a good list of MIME types.