A concert and oratorio singer, Boatwright continued performing in public well into her 90s, The New York Times said.
Boatwright died Wednesday, her son, Howard Leake Boatwright III, said.
She gave world premiere performances of some of Charles Ives' songs and, with pianist John Kirkpatrick, made the first extensive recording of his music.
She performed with conductors Leopold Stokowski, Erich Leinsdorf, Seiji Ozawa and Zubin Mehta, and sang at the White House for President John F. Kennedy in 1963.
Boatwright was born Helena Johanna Strassburger on May 17, 1916 in Sheboygan, Wis., and was the youngest of six children. Bach chorales in four-part harmony were sung nightly around the dinner table, the Times said.
In 1943, she married Howard Leake Boatwright Jr., a violinist and composer, who died in 1999.
Boatwright is survived by two sons and a daughter.