Mama dolphins sing to their babies in the womb. Dolphins use signature whistles to identify themselves, and expecting mothers have been observed performing a new whistle close to the time of birth and for two weeks after. Researchers think it may be a form of imprinting, which could explain why other nearby dolphins grow quieter during this time. Source

Instead of building inland aquariums and putting whales and dolphins in tanks, why don’t we just set up a bunch of floating bleachers on big pontoons out on the waterfront and bribe the whales to come put on a little show? They’d totally do it - they’re smart enough to understand transactional arrangements.