I'd suggest after leveling to not complete any character tasks with a quest associated until you've visited other towns and clicked a few of your own buildings. Every harp I've got was after leveling and completing a task. Maybe superstition.
The donut glitch is worth 20 mins of patience. Harp glitch seems to happen when you collect from all the buildings and characters and before it collects you level up also. So if your close I would have everyone in the pub if you want it. I have an iphone5 so I don't care if I get it. Your trying to overload the system.
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