Character Analysis
Whatever your views on organized religion, it's hard not to like Father Arguedas. He's young, smart, and brave, and he works hard to take care of other people (2.105). He refuses to leave the hostage crisis twice (2.184, 3.179) and he says last rites for the dying accompanist when it's clear he's beyond earthly help.
Father Arguedas does all this even though the terrorists are telling him to stop, and they could easily shoot him (3.28-52). Throughout the book, Father Arguedas is generous and earnest, but realistic too. Even if being realistic sometimes means risking his life.
He's also a serious opera fan. The narrator tells us that "Lacking any real or interesting sins to confess, he [Father Arguedas] offered up the imagined sin of opera one Wednesday afternoon as his greatest sacrifice to Christ" (2.106). Luckily for him, the priest hearing his confession replies, "Verdi or Wagner?" (2.107) and tells him that opera isn't a sin (2.111).
Father Arguedas' good qualities and love for opera don't just make us think he's a great guy with an interest in art. They work in the structure of the book as a whole, too. He's the guy who knows a nearby music teacher and is able to help Roxane Coss get her super-important box of music (5.52-103). That box transforms the whole situation and is the catalyst for the community that springs up in the house (see our character analysis of Roxane Coss for details).
Basically, Father Arguedas helps bring the music to the party. And the music pretty much creates the party in a house that otherwise would have been full of terrorists and their hostages.
Father Arguedas is also one of the characters through whom the book explores the ways that art transcends everyday experience. As a priest, Father Arguedas already has the language of spirituality to describe things beyond everyday knowledge, and he often uses that language to describe opera as well. Like when he realizes with relief that opera is not a sin:
Father Arguedas took his small, perfunctory penance and said each prayer three times as an offering of joy. He did not have to give up his love [opera]. In fact, after that he changed his mind completely and decided that such beauty would have to be one with God. The music gave praise, he was sure of that, and if the words too often focused on the sins of man, well, did Jesus himself not explore this subject exactly? (2.112)
Father Arguedas is one of the characters who shows the power of art, but he's also one of the few characters who remains relatively aware of the world outside the house, maybe because he's deeply connected to his city and his community by his role serving there as a priest. At the end of the book almost everyone has forgotten the outside world, but Father Arguedas remembers. Part of him really wants to stay in the world created in the house, but he also keeps a grasp on reality.
The book describes that realistic view when Oscar Mendoza and Ruben Iglesias are talking about giving Ishmael a job and adopting him:
He [Father Arguedas] felt something cold and startling move through his heart. The men should not be talking to Ishmael this way. They were forgetting the circumstances. The only way things could work would be for everything to stay exactly as it was, for no one to speak of the future as if speaking of it could bring it on. (9.147)
Father Arguedas does a lot in the book, including showing the reader something about art, courage, and the looming realities of the everyday world as all those things play out in Bel Canto.