Joanna Simon, an acclaimed mezzo-soprano and one of the three singing Simon sisters – who include pop star Carly, has died at the age of 85.

Joanna, the eldest of four, died on Wednesday, just a day before her sister Lucy died, according to Lucy’s daughter Julie Simon.

Their brother Peter, a photographer, died in 2018 at the age of 71. All three had cancer.

Obit Lucy Simon
Lucy and Carly Simon sing in Broadway’s Shubert Alley in New York (Nancy Kaye/AP)

“In the last two days, I’ve been by the side of both my mother and my aunt, Joanna, and watched them pass into the next world. I can’t truly comprehend this,” Julie wrote on Facebook.

Joanna, who died of thyroid cancer, rose to fame in the opera world and as a concert performer in the 1960s.

She was a frequent guest on TV talk shows. After her retirement from singing, she became an arts correspondent for PBS’s MacNeil-Lehrer News Hour, where she won an Emmy in 1991 for a report on mental illness and creativity.

“I am filled with sorrow to speak about the passing of Joanna and Lucy Simon. Their loss will be long and haunting. As sad as this day is, it’s impossible to mourn them without celebrating their incredible lives that they lived,” Carly said in a statement on Saturday.

She added: “We were three sisters who not only took turns blazing trails and marking courses for one another. We were each other’s secret shares. The co-keepers of each other’s memories.”

Joanna was married to novelist and journalist Gerald Walker from 1976 until his death in 2004. She was the companion of Walter Cronkite from 2005 until his death in 2009.

On stage, she made her professional debut in 1962 as Cherubino in Mozart’s The Marriage Of Figaro at New York City Opera.

That year, she won the Marian Anderson Award for promising young singers. She took on a range of material. As a concert performer, she leaned into classic and contemporary songs of her time.

The siblings were born to publishing giant Richard Simon and his wife, Andrea.

Carly and Lucy once performed as the Simon Sisters, opening for other acts in Greenwich Village folk clubs.