She was 75, and had suffered from a neurological disorder, according to the paper.
Argento studied at the Peabody Conservatory, where she met her husband, and at the Eastman School of Music. In 1958, the two moved to the Twin Cities, where Dominick Argento taught at the University of Minnesota.
In addition to performing her husband's works, Argento appeared in leading roles with the Center Opera Company, the predecessor to the Minnesota Opera, and with various choirs and madrigal groups. She retired in the 1970s.
Dominick Argento, the composer of The Aspern Papers and other operas, told the Star Tribune that his wife was a major influence on his writing. "She gave me a lot of help when I was writing for the voice," he said. "What I learned is from her."