Kitty Kallen, the silken-voiced pop singer who sang with some of the most popular big bands of the 1940s — including groups led by Artie Shaw, Jimmy Dorsey and Harry James — and who achieved her biggest success as a solo artist with the 1954 chart-topping hit “Little Things Mean a Lot,” died Jan. 7 at her home in Cuernavaca, Mexico. She was 94.

Her son, Jonathan Granoff, confirmed the death but did not cite a specific cause.

A onetime child radio star in Philadelphia, Ms. Kallen grew into a singer who evinced an expressive style on both sweet and bluesy numbers. Her rise was also propelled by a comely appearance, and she was often introduced as “Pretty Kitty Kallen.”

She was in her teens when she was touring and recording with the venerated trombonist-bandleader Jack Teagarden, whom she regarded as her most important mentor. Teagarden, she once said, instructed her to “sing the melody, read the lyric but tell the story.”

After she replaced Helen O’Connell as Dorsey’s thrush in 1943, Ms. Kallen became one of the best-known female singers in the nation. Among their major hits was a version of “Besame Mucho” in a duet with the band’s male singer, Bob Eberly, as well as “When They Ask About You” and “They’re Either Too Young or Too Old,” a woman’s lament about the available men on the homefront during World War II.

Ms. Kallen in 1955. (Mirrorpix/Everett Collection)

Ms. Kallen, who was Jewish, left for the James outfit in early 1944, in part because of what she told James biographer Peter J. Levinson was Dorsey’s anti-Semitism.

With James for the next two years, she continued a solid run of top-selling recordings, including “I’m Beginning to See the Light,” “I’ll Buy That Dream,” “In Times Like These” and “11:60 P.M.” She had a No.1. hit with “It’s Been a Long, Long Time,” which captured the mood of soldiers returning to their sweethearts.

She counted her years with James, a celebrated trumpeter, as some of the most rewarding of her professional life. “Working with Harry wasn’t work,” she told Levinson. “You knew you were on that bandstand because he liked what you were doing. You never had to be stroked or patted on the back, and there was never any kind of pressure.”

Buoyed by her success with James, Ms. Kallen left for a solo career that included singing on Shaw’s inventive 1946 version of “My Heart Belongs to Daddy” — with its pulsing jazz riffs and allusions to Jewish klezmer music — and 1954’s “Little Things Mean a Lot” and “In the Chapel in the Moonlight.”

She also performed in nightclubs such as the Copacabana in New York and concert halls including the Palladium in London, and she appeared with Dean Martin and Jerry Lewis on “The Colgate Comedy Hour” TV variety show.

The ascendance of rock-and-roll and her struggles with a vocal-cord problem largely sidelined her by the late 1950s. One of her last songs in the top 20 was “My Coloring Book” in 1962. Her career ended for good about four years later when she developed blood clots in her lungs.

Although some sources give her birth name as Katherine Kalinsky, she was born in Philadelphia as Katie Kallen on May 25, 1921, as best her son can discern from records.

She was a child when her mother died of cancer. She later wrote that her father, a barber, was a “rather helpless man” who “had a difficult time keeping his six children supplied with clothes and food, to say nothing of love.”

She began singing publicly at 12 or so, when she won first prize — a camera — in an amateur-hour singing contest. She said her father refused to believe that she had won and punished her — until neighbors came around to congratulate his daughter.

She earned money doing commercial jingles and sang on “The Children’s Hour,” a popular radio program sponsored by the Horn & Hardart cafeteria chain in New York and Philadelphia.

Ms. Kallen soon had her own program on the Philadelphia airwaves. And within a few years, she was on the road singing with the big bands of Jan Savitt and Teagarden. She sang briefly with the band of Bobby Sherwood, with whom she recorded “Moonlight Becomes You,” before joining Dorsey.

Her first marriage, to Teagarden clarinetist Clint Garvin, ended in divorce. In 1948, she married Budd Granoff, a Broadway press agent who became her manager. Granoff later was a TV game show producer and worked in a syndication partnership with Chuck Barris, the game-show host.

The Granoffs also were deeply involved with the Society of Singers, a nonprofit foundation known as S.O.S. that aids performers who have fallen into dire financial need.

Granoff died in 1996. Survivors include her son, a lawyer who lives in Bala Cynwyd, Pa., and is president of the New York-based Global Security Institute; and three grandsons.

Ms. Kallen’s career had a strange coda involving multiple imposters.

Her death was widely reported in 1978, when Genevieve Agostinello, a woman who had checked into a Los Angeles-area hospital as Ms. Kallen, died. When an Associated Press reporter reached out to the real Ms. Kallen, she sang “Little Things Mean a Lot” to convince him she was still very much alive.

Another Kallen fraudster popped up in 1989 in New Port Richey, Fla. The woman, Edna Garrett, called in to a Florida radio station, appeared at social events and became a minor celebrity among the many retirees in her community who still adored the once-famous singer.

Garrett’s inability to sing aroused some suspicions. The charade ended only after the real Ms. Kallen’s picture appeared in a supermarket tabloid and ABC News followed up.

Again, Ms. Kallen was flummoxed. She told the network, “Bizarre. Crazy. Why me? Why me? What is it? What is it with these people? I said to Budd, I said, ‘This has got to stop.’ Suppose, indeed, this woman had died, and I had to read my obit again. Couldn’t do it.”