Perhaps that’s a little unfair; after all, most large churches take more than a few years to complete, but San Petronio is special. It’s not only not complete, there is not even an architectural plan for its raw and unfinished facade!
That’s not all that’s special about San Petronio; it’s immense. Big enough to rank as the 15th-largest church in the world, and absolutely the largest brick church in the world. How big? It’s half again the length of a football field (139 meters) and 66 meters wide. The top of the vault is 45 meters up, nearly the height of a 15-story building.
Although construction started in 1390, and services have been held there since early in the 15th century, it wasn’t consecrated until 1954…and thereby hangs another tale. The building was a project of the secular authorities, the city of Bologna, and not the church, which looked on the project with distinctly mixed feelings…especially when one of the plans for its completion would have made it larger than Rome’s Saint Peter.
It only came under control of the church in 1929, when the Pope and Mussolini signed an agreement, the so-called Vatican Concordat. In 2000, the relics of Saint Petronius, Bologna’s patron, were finally moved there.
Over time, a half-dozen architects were commissioned to design the facade—including Palladio—but none were ever accepted, and there’s no plan today except to keep restoring what’s there. When we visited in 2012, that included wrapping the front of the building with a gauze scrim printed with the image of the area hidden by construction.
One more distinction for this magnificent church: It has a long history as a center for music, going back to the 1400s, and played an important role in Baroque music with its two large organs, built in 1476 and 1596, both working and in nearly original condition. Here’s a YouTube video with a sonata by Torelli, played in San Petronius on the organ for which it was written.