Overhead, the five great barrel vaults spanning the nave repeat the Mediterranean color scheme used in the apse.
At the base of four vaults are the clerestory "Singing Windows." The fifth vault takes flight from John Dryden's poem, Song for Saint Cecilia's Day.
The minor vaults have a background of terra cotta, a foliate pattern in grisaille, bordered in blue, arches across each vault--a design echoing the Moorish arabesque in the ambulatory lunettes.
The high point of each vault, seventy-seven feet above the nave floor, is centered with a tondo. Four of these round paintings depict the Evangelists, whose gospels form the cornerstone of the Catholic faith. The symbolic descriptions of the Evangelists are found in the Book of Revelations. John, the most mystical, is represented as an eagle since these soaring birds were believed able to look directly into the sun. The gospel of Luke describes a more ordinary strength, comparable to a gentle ox. Mark's gospel focuses on the majestic power of Christ, hence his representation as a lion. John's writing concerns Christ's genealogy and incarnation as a man.
In the chancel vault, Christ the Redeemer is symbolized by the pelican. The pelican was believed to sacrifice itself by nourishing her chicks with blood pecked from her own breasts. Dante referred to Christ as nostro pelicano whose blood was shed to save his "children."
The ribs are ribbons of terra cotta, edged in gold and intertwined with gilded acanthus rosettes. The rib borders have a "bound sheaves" design.
~ The Beauty of Thy House, 2005