Born as
Ruth Maxine Kahn in
Des Moines, Iowa, Kobart studied opera at the
American Conservatory of Music in
Chicago and made her professional debut as the Witch in an
off-Broadway production of
Engelbert Humperdinck's
Hänsel und Gretel. She frequently toured with the
NBC Opera Theatre (NBCOT) and the
New York City Opera (NYCO). With the NBCOT she notably created the role of Agata in the world premiere of
Gian Carlo Menotti's
Maria Golovin at the
Expo '58 in
Brussels on August 20, 1958; later the same year she portrayed the role on
Broadway. For the NBC, she also created the role of Arina in the premiere of
Bohuslav Martinů's
The Marriage. She played Madame Pace in the world premiere of
Hugo Weisgall's
Six Characters in Search of an Author at the NYCO in 1959. Regarding her role as Madame Pernelle in
Tartuffe at the Geary Theater, she wrote: "I had a big voice and a big body ... I came out on stage and shouted my head off, and believe it or not, I found my way." In 1955, Kobart made her Broadway debut in the chorus of
Rodgers and Hammerstein's
Pipe Dream. She understudied leading lady
Helen Traubel and played her role forty two times during the show's run. Additional Broadway credits included
How to Succeed in Business Without Really Trying,
A Funny Thing Happened on the Way to the Forum,
A Flea in Her Ear, and
Three Sisters. She was nominated for the 1963
Tony Award for Best Featured Actress in a Musical for
Forum. Kobart's association with
San Francisco's
American Conservatory Theater began with its first season in 1967 and lasted through 1994. Her appearances with them included
The House of Bernarda Alba,
Sunday in the Park with George,
Arsenic and Old Lace,
A Little Night Music, and
Home. In the 1970s she took an extended leave from the company to portray
Nurse Ratched in the 18-month-long San Francisco production of ''
One Flew Over the Cuckoo's Nest. Her national tour credits included Forty Carats, The Last of the Red Hot Lovers, and Annie. Her portrayal of Miss Hannigan on the first tour of Annie'' and in a long Chicago run (in succession to originator
Dorothy Loudon) was considered one of the best interpretations of that classic role. She voiced the main villain, Malicia, in the 1994 video game ''
King's Quest VII''. Kobart was
Jewish and was a member of the
Temple Israel of Hollywood. ==Films and television==