How did the nightingale die in Frog and Nightingale?

The cunning frog pressurized the nightingale to practice more and longer in order to improve the tonal quality of her voice, by taking advantage of the bird’s innocence. He also set his eyes on better billings by making a show of her performance. The foolish bird danced to the tune of her master and lost the sweetness of her voice due to long hour of practice. The hoarse and quivering voice began to leave the audience annoyed and tired. To see a dip in ticket sales, the frog teased her as ‘brainless bird’ and instructed her to puff her lungs out of passion. One day a vein burst due to excessive stress on the lungs, and the poor bird died.