"She was very family oriented," Gaither said. "She was more than just a star or a famous personality. She was a person of her own."
Gaining fame in the 1960s as a nightclub singer, McNair graduated to film and television as opportunities were opening up for black women late in the decade. She made her Hollywood acting debut in 1968 in the film, "If He Hollers, Let Him Go."
She later starred with Elvis Presley in his 1969 film "Change of Habit" and as Poitier's wife in the 1970 film "They Call Me MISTER Tibbs!"
She found movie acting "a more rewarding kind of work than singing," she told The Washington Post in 1969. "When I'm working in a club, I must go from one song to another rapidly and I don't have much time to express myself emotionally. In a movie, you can concentrate on one scene at a time."
She hosted television's "The Barbara McNair Show," a syndicated musical and comedy program, from 1969 to 1972.
As a singer, one of her biggest hits was "You Could Never Love Him." She started out as a jazz singer but later branched out, adding show tunes and the Beatles' "Yesterday" to her repertoire.
On Broadway, McNair replaced Diahann Carroll in Richard Rodgers' "No Strings" in 1963, and 10 years later co-starred with Hal Linden in a revival of "The Pajama Game."
Gaither said her sister seemed headed for a career in show business from the time she was a girl in Racine, Wisconsin.
"She sang from the time she was five years old in churches and then at school," Gaither told the Racine Journal Times. "We always encouraged her."
McNair went to the University of California, Los Angeles, before moving to New York City to pursue her dream of becoming an entertainer.
An engagement in 1957 at the Village Vanguard earned her notices that would lead to her Broadway debut in the short-lived 1958 musical "The Body Beautiful."
Reviewing a nightclub appearance in late 1965, a New York Times writer commented that the "strikingly beautiful" McNair "does not have to depend on looks alone. She is a highly knowledgeable performer who projects an aura of beauty, a warm personality and an appealing sense of fun."
As she gained notice in Hollywood in the late 1960s, she told the Post that a steamy 1968 photo spread she did for Playboy "helped my career immensely."
Also around that time, she joined a Bob Hope tour to entertain servicemen in Vietnam, saying she was thrilled to later meet men who had seen her there. "I don't believe in war for any reason," she told the Post. "I went over there to see what war was like and to comfort the men and I was appalled."
Her career was hampered in 1972, when she was accused of drug possession along with her then-husband, Rick Manzie, after she signed for a package delivered to her dressing room. She was later cleared; Manzie was shot to death in 1976.
"You can spend all this time building something and it can be destroyed in a minute," she told the Post in 1979.
But she still made TV appearances into the 1980s on such shows as "The Jeffersons" and "The Redd Foxx Show." Her sister said she sang professionally until the middle of last year, when the spreading cancer hurt her ability to perform.
Along with Gaither, McNair is survived by her fourth husband, Charles Blecka.
"She had a great resume," Blecka said. "She could have ended up conceited, but nothing ended up that way. She had a special quality that was infectious, that everybody loved."
(Copyright 2007 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.)
