Tranquil- free from disturbance; calm.
Eliza tried humming it before she tried to sing the song.
The best answers to the incomplete statements above would be that based on the interactions between Pahom and the Devil, Pahom is the type of character known as the protagonist while the Devil is intended to be as the antagonist. The former is usually the main character of the story and the latter is the villain.
Paraphrase the poem is the answer