Virginia O’Brien, who has died aged 79, appeared in 16 movies between 1940 and 1947, mostly in small roles or merely to deliver a speciality number or two. Yet this singular singer was very much part of that great escapist era during which MGM musicals dominated.O’Brien, nicknamed variously The Diva of Deadpan and Miss Red Hot Frozen Face, was an attractive brunette, with a deep voice, who delivered her songs in an unsmiling sphinx-like manner, her lovely dark eyes unblinking, her face hardly moving a muscle, although her neck sometimes jutted back and forwards.

A typically memorable moment was her acidly comic rendering of In A Little Spanish Town in the all-star cavalcade Thousands Cheer (1943), in contrast to the sweetly-sung version by Gloria De Haven and June Allyson, who flanked her. In Ziegfeld Follies (1946), after Fred Astaire has sung Bring On The Beautiful Girls – who appear in pink, on a merry-go-round, seated on live horses – the staring O’Brien, astride a vigorous fake white horse, pleads Bring On The Wonderful Men.

Born in Los Angeles, Virginia Lee O’Brien was related to Civil War General Robert E Lee, and she was named after his home state. Her Irish father was the captain of detectives of the Los Angeles Police Department and later the city’s deputy district attorney. One of her uncles was the film director Lloyd Bacon, whose credits include 42nd Street.

At North Hollywood high school, Virginia took dancing and singing lessons. In 1939, aged 17, modelling herself on her idol, Ethel Merman, “moving my arms and singing up a storm,” in the stage show Meet the People, she won an MGM contract.

Before she made her screen debut, however, O’Brien appeared on Broadway in the revue Keep Off The Grass, which starred Jimmy Durante. New York Times critic Brooks Atkinson called her, “a deadpan singer who convulses the audience by removing the ecstasy from high pressure music”.

Her first film for MGM, Hullabaloo (1940), in which she played a wisecracking manicurist, allowed her to interpret two songs in her inimitable poker-faced style. In Lady Be Good (1941), she partnered comedian Red Skelton for the first time as his kooky girlfriend, who is only happy “when she’s eating”. In the Marx Brothers comedy, The Big Store (1941), she was a salesgirl whose raucous rendition of Rock-A-Bye-Baby would have woken any tiny tot. She delivered three numbers in Panama Hattie (1941), including Did I Get Stinkin’ At The Savoy?, which the star of the film, Ann Sothern, refused to sing because she thought it in bad taste. O’Brien, with her expressionless delivery, managed to get away with it.

In 1942, she married actor Kirk Alyn, who was to become the Superman of serials after the war. They had two daughters and a son. In fact, she was pregnant with her first child while making the exuberant Judy Garland musical The Harvey Girls (1946). As Alma, one of the waitresses out west, her part got smaller and smaller as she got larger. Still, she had an enchanting number with Garland and Cyd Charisse in night-gowns called It’s A Great Big World.

Her largest previous role had been as the lovestruck cigarette girl in love with Red Skelton in Du Barry Was A Lady (1943), in which she sang Salome Was The Grandma of Them All. In Meet The People (1944), O’Brien sang Say We’re Sweethearts Again, which contains the lyric “I never knew our romance had ended till you tried to poison my food.” It became her most requested song when she did cabaret.

Her penultimate picture at MGM was the Jerome Kern biopic Till The Clouds Roll By (1946), in which she performed Life Upon The Wicked Stage, and A Fine Romance. She was then co-starred with Red Skelton again in Merton Of The Movies (1947).

Of her role, Variety wrote “Virginia O’Brien proves herself a capable leading lady without recourse to deadpan vocaling. The erstwhile canary doesn’t have a number to chirp throughout and sells herself strictly on talent merits in the romantic lead opposite Skelton. The manner in which she delivers should further her career.”

Alas, it was not to be, and when MGM failed to replace Garland with O’Brien in Annie Get Your Gun, mainly because she admitted she had a fear of horses, they did not renew her contract.

In 1955, she divorced Kirk Alyn (who died in 1999), and took a small role as a nurse in Francis In The Navy, starring Donald O’Connor and a talking mule. In 1957 she married electronics engineer Vern Evans, a marriage which produced a daughter. In 1968, after a divorce, she wed aviator and inventor Harry B White, a marriage which lasted until his death in 1996.

During the next two decades, O’Brien would appear in many comedy and variety series on television, and she also toured in a number of road companies. In 1983 she recorded a live performance album of her act at the Hollywood Masquer’s Club, which included many of the songs that made her famous.

• Virginia O’Brien, actress and singer, born April 8 1921; died January 18 2001.

The above “Guardian” obituary can also be accessed online here.