Generic Phrases

What is the difference between these two prepositional phrases?

1. At the beginning.... 2. In the beginning....

Public Comments

1. With 1, you would usually say it when you're at an event or location. "At the ballpark we ate hotdogs." With 2, it refers more to a time. So "In the beginning of the play, we met the characters." There's not a huge difference; it's a slight one.
2. 'At the beginning' implies a singular event which was instantaneous or nearly so; e.g. ' At the beginning of the meal she lit the candles' 'In the beginning' implies an event which had some duration; e.g. went on over 6 days