Giovanni Boccaccio’s notorious Decameron inspired everyone from Shakespeare to Pablo Pasolini. The sacred and profane stories of plague-ridden 14th century Florence Italy are full of disease, sex, murder, transfiguration, religious tyranny, moral decay and heartbreak – all the ingredients for opera. Under the direction of Karen Salliant, Philadelphia’s International Opera Theater and their counterpart company in Italy have turned Boccaccio’s text into a raucous opera of dramatic and comedic grandeur.

Since Boccaccio’s text had a different narrator for each novella, the opera has appropriately utilized the improbable assemblage of seven Philadelphia-based composers, working on a different Decameron story. Instead of musical chaos, the various musical voices works well. The composers – Efrain Amaya, Michael Djupstrom, Daniel Shapiro, Adam Silverman, Tonoy Solitro, Thomas Whitman and Ya-Jhu Yang- build the broad musical template that is cohesive. Credit the fine libretto, written by Salliant and Tommaso Sabbitini, who maintain muscled interaction to the music, alternating song cycles in Italian and English.

Whitman’s front scenes introduce Calandrino, the artist who spins fantasies that helps him escape the grim reality of the plague. Baritone Bernard Bygott is a feverishly inspired troubadour, his physical comedy full of mischief but doesn’t steal from his earnest vocal performance. As Italian folk dances and tarantella beats swirl around, he reads from his shredded garments as he sings about the horrors of the plague with gallows humor and clinical crassness. The other lead cast member plays noble and ignoble characters over the nine stories depicted.

Among the many highlights – Yasko Fuiji who is transcendent in the Ghismunda and The Heart of Guiscardo – the stunner that ends Act I. The story is about an heiress in love with a household servant who is murdered by her father. She holds his heart in her hand as Amaya’s music blooms with the most grotesque beauty. Fuiji’s sings this horrific scene with such power and truth. Kathryn Krasovec, singing the mezzo roles, is most sumptuous as Madre Usimbalda, lamenting the loss of her children. The tenor Son Jae Yeon, can play priest, clown and villain, with equal ease and is vocally thrilling in all of them. But the baritone Christopher Grundy, stepping in just days before the premiere, in the lover roles, sometimes with lengthy soliloquy, who gives no less than a heroic performance.

Salliant, who also directed, didn’t have much to work with at the modest black box upstairs at the Prince Music Theater, but she compensates by keeping the action focused on the performances and music. Great costuming of different textures (medieval headdress; wedding gowns, viscount capes and celestial tunics) play off an ocean of tulle, which morphs into clouds, sickbeds and ethereal set pieces at any moment.

Musical director Gianmaria Griglio achieved fine detailing from the International Opera Theater Chamber Orchestra, which sounded twice the size at any given moment. Befitting its source material, Decameron, the opera, deserves a long artistic life.