Christina Massimei stood silent in the center of the living room, her shoulders squared, her eyes focused on the voice teacher seated at the Steinway grand.
The teacher played the introduction to Mozart's "Alleluia." Massimei opened her mouth. And a sound came out that was half voice-of-the-angels, half TNT explosion, climbing the walls of the modest practice space and all but shaking the windows.
Massimei, an operatic soprano from Bel Air, was rehearsing for the biggest performance of her life: serving as cantor — the lead liturgical singer — for the historic Mass that Pope Francis will celebrate Wednesday afternoon in Washington.
She won't need...