Any summary of Seth's poem is going to start with the basic exposition of the poem. This frog lives in a bog and croaks as the sole sound throughout the bog. All the other inhabitants have gotten accustomed to the fact that his monotone drone as the "only game in town." For his part, the frog enjoys that he has the monopoly of sound. With the nightingale's entrance and her entrancing songs, a couple of realities emerge. The first is that the frog now has competition for "Bog Idol," so to speak. Additionally, the competition is actually better than his song. It has much more melody, greater harmony, and has excited the other inhabitants of the bog. The frog moves to checking this growth by taking on the role of mentor and elder voice of reason to the nightingale, suggesting that he can help to make her "better." The nightingale is excited by the idea of having a "mentor" or "coach," and does exactly what the frog says. The frog forces her to expend all of her energy and essentially ruins her voice so that she can no longer sing and with her absence, the frog returns to being the sole voice in the bog, the consolidator of all musical power.
The poet, Vikram Seth, very cleverly gives us a message of the importance of self-confidence and moral courage in his poem - The 'Frog and the Nightingale'. Once in a bog, a frog sat under a Sumac tree and croaked all night in a loud and unpleasant voice. The other creatures loathed his voice but their complaints, insults and brickbats couldn't stop him from croaking stubbornly and pompously, insensitive to the disturbance he was causing.
Then, one night a nightingale appears at the bog. Her melodious voice captures the admiring attention of the creatures of the Bingle Bog. Ducks and herons swim towards the Sumac tree to hear the nightingale serenade. Some lonely creature even weeps hearing her song. When she stops, there is thunderous applause with the creatures demanding a repeat performance (encore). The jealous frog disturbed by the intrusion of a challenging rival listens to the nightingale dumbstruck.
Next night, when the modest bird prepares to sing, the plotting frog interrupts and posing as a music critic, says that the technique was fine, of course, but it lacks a certain force. Unassuming and not used to any kind of criticism, she defends herself by saying, "At least its mine".
The nightingale soon became famous and the frog grew richer, earning money from her concerts. Eminent personalities like the Owl (Earl) of Sandwich and Duck (Duke) of Kent attend the concerts. The frog sat and watched with mixed feelings of happiness and bitterness. Happy because he was earning money and jealous because the bird was receiving so much attention.
Meanwhile, the frog makes the nightingale rehearse hard even when it rained and constantly criticized and abused her, ensuring that she became broken in spirit. Fired and spent, her voice lost its beauty and the creatures stopped coming to hear her sing. Morose and depressed, she refused to sing, but the frog goaded her to practice. Scared and unhappy, the nightingale tried, burst a vein, and died.