I love whale sounds so much. So I was happy to find archive.org's audio section had some..

Whale Sounds, Humpback Whale (Megaptera novaeangliae) Humpback whale song is thought to be a male breeding display that is prominent in their wintering grounds, and previously thought to be quite rare in the feeding areas. It is called a song because it is a long, complex vocalization that repeats in a predictable pattern. Whale song recordings from Glacier Bay have been made only in the fall, when perhaps the hormonal changes that spur whales to migrate are beginning to occur.

Feeding call is a sterotyped vocalization typically used during humpback whale coordinated group feeding. In the Glacier Bay area, it typically occurs 15-20 seconds before a group of whales all surface together after a foraging dive. This specialized call is common in some localities but rare in others. It may be used for group coordination, (ready, set, go!) or to scare/concentrate the schooling fish that are their prey.

Listen to the sounds here