Emil Petrovics's oratorio, Book of Jonah, is inspired by the work of the same name by the refined Hungarian poet Mihály Babits (1883-1941). It was premiered in 1967. Its musical language is a continuation of Petrovics's successful opera, C'est la guerre. It is suffused with a melodic character that derives intimately from the intonation of the Hungarian language, and is united with the achievements of European music. For the dramaturgy of the oratorio, Petrovics takes the unusual step of assigning the chorus three dramatic roles: it narrates, comments and participates. It thus united the former “testo” and “turbo” division of roles of traditional oratorio practice.
First part. The Lord sends Jonah to Nineveh to preach against evil. The prophet however embarks on a boat for Tarsis to evade this command. An immense storm descends upon them and the terrified sailors, urged on by the captain, launch the disobedient Jonah into the waves. The sea then calms and a rainbow appears in the sky.

Second part. An immense whale swallows Jonah. He prays to the Lord from its stomach for his freedom, and proclaims the faith. After three days and three nights of woe, the Lord finally relents. The whale regurgitates Jonah the Prophet onto dry land.
Third part (attacca). The Lord repeats his command and Jonah sets off to Nineveh to preach. He first harangues a market, but the merchants merely laugh at him. Then he preaches to actors telling them that in forty days, Nineveh will be destroyed. The comedians appreciate the prophet's passion but they have no grasp of the meaning of his words. Jonah is now awaited in the royal court: he is placed atop a pillar from where he can preach. They make fun of him and Jonah curses the entire city before rushing into the desert. He demands of the Lord the fulfilment of his prediction: that Nineveh should be destroyed. But when the fortieth day comes, the city remains unharmed.
Fourt part. Jonah in his desperation and shame, places the blame squarely on the Lord: You through me into slander, for I did lie, and so did my calendar. And God did lie too! He explains he knew this would happen: that is why he wanted peace and tried to escape to Tarsis. However the Lord takes pity on Nineveh, humanity, human aspirations and work. The Jonahs of this world should only preach, the Lord himself will act: the new Ninevehs will be better. Jonah is deeply moved to hear these words, and before his eyes, he sees the contours of the peaceful, intact city.

Epilogue (Jonah's prayer). The prophet has finally understood everything. He entreaties the Lord to be restored his fervour of old, and to speak “until the powers, cosmic and Ninevean will silence me and send me to oblivion.”