From the press release:
Not only in town to perform to sell-out crowds, Harvey and the Humpbacks will be hard at work on a hit new song that will travel through migrating pods around the world. Researchers at The University of Queensland have found that male humpback whales ‘change their tune' every year during their migration across the Pacific. UQ PhD student Ellen Garland said, just like rock stars, no humpback wants to become irrelevant. “We believe the song is continually changing because the males wish to be novel or slightly different to the male singing next to them.”
Amy's New Whale Design: