"The best piano accompanists are seldom noticed by audiences," The Washington Post observed in December in a profile describing Dianne Shupp, 66, who died of breast cancer Oct. 10 at a daughter's home in Woodbridge.

In a career that spanned more than 40 years, Mrs. Shupp, as The Post noted, was portrayed by her peers as "accompanist par excellence, beyond comparison." She was a first-call pianist who "could blend with the best of them."

A longtime Sterling resident, she accompanied all choruses at George Mason University for 14 years, where she also was a musical coach for vocal soloists. She also was resident pianist for the New Dominion Chorale, church organist for Sydenstricker United Methodist Church in Springfield, and founding pianist for the McLean Choral Society and the McLean Symphony Orchestra.

Dianne Ethel Shupp was born in Allentown, Pa., the eldest of three children. Her father, a carpenter, wanted her to become a concert pianist and, when she was 5, took her to see pianist Arthur Rubenstein. "I was enthralled at the whole thing," she told The Post last year.

As a child, she listened mostly to classical music. "I knew I wanted to go to music school," she said. After graduating from high school, she was accepted at the Eastman School of Music in Rochester, N.Y., but dropped out after a year to marry Lloyd Shupp.

She moved to the Washington area in 1958 and essentially stopped playing. Her marriage ended in divorce after 22 years, and she was left to raise seven children as a single mother.

"I raised them alone and worked in a restaurant," she told The Post. "It was very difficult. The kids and I were very close. That's how we made it work."

As the children grew, she gradually began playing again -- giving piano lessons at home, playing professionally and teaching at GMU. Reviews over the past 15 years were often effusive, with such adjectives as "heroic," "powerful" and "marvelous" used to describe her accompaniment.

She had mastered the accompanist's subtle art -- blending in, performing inconspicuously, providing support and helping make the soloist shine.

"It's just what I love to do," she said in December.

Survivors include seven children, Mike Shupp of Falls Church, Steve Shupp of Richmond, Carolyn Xanten of Woodbridge, Kathy Valtin of Colorado Springs, Bob Shupp of Annandale, David Shupp of Herndon and Bill Shupp of Los Angeles; two sisters; and 11 grandchildren.