There are music controls by default on the S3, at least on my Verizon Galaxy S3. Only thing is that it is not on the lock screen but rather the notification pulldown menu. You have to pull down and use them from there.
It's possible, to control your stock music player from lock screen with password. Just simply, -before you set a passcode, or any security for the lock screen- go to Steeings-My device-Lock screen-Lock screen widgets, than turn off the "Favorite apps or Camera" option. After this you can set a passcode, and from the lock screen, now you can control you stock music player.