Catherine Annette Hanshaw was born on October 18, 1901 to Frank Wayne Hanshaw (1873–1927) and Mary Gertrude McCoy (1874–1959) in their residence in Manhattan. She had two brothers, George and Frank. Her father loved show-business and music; he ran away to join the circus, but he returned. Her aunt Nellie McCoy and Bob "Uke" Hanshaw were vaudeville performers. She sang for guests at hotels owned by her father and demoed sheet music at her family's music shop, The Melody Shop, in Mount Kisco, New York. Hanshaw aspired to be a portrait painter, studying at the National School of Design for a year. Her professional music career started when she was paid to sing for society and birthday parties.
Before recording, in 1926, Hanshaw sang on local radio stations while visiting Florida with her family. Her first recording is a demo featuring a medley of popular songs for Pathé. Her first commercial recordings are "Black Bottom" and "Six Feet of Papa," recorded on September 12 and 18. She recorded for Pathé until 1928; Pathé released her sides on both the Pathé and the Perfect labels. Starting in June 1928, she recorded for Columbia; most of these recordings were issued on their dime-store labels Harmony, Diva, Clarion and Velvet Tone. A handful were also released on their regular-priced Columbia and OKeh labels. Although most were released under her name, she was renamed Gay Ellis (for sentimental numbers) and Dot Dare or Patsy Young (for her Helen Kane impersonations). She recorded under a number of other pseudonyms, including Ethel Bingham, Marion Lee, Janet Shaw, and Lelia Sandford. Starting in August 1932, she began recording for ARC; her recordings were issued on their Melotone, Perfect, Conqueror, Oriole and Romeo labels. Her final session, on February 3, 1934, was placed on ARC's Vocalion label.
Throughout her recording career, she sang with the Original Memphis Five, Willard Robison's Deep River Orchestra, Sam Lanin's Orchestra, Lou Gold's Orchestra, and Rudy Vallée's Connecticut Yankees. She had been accompanied by Red Nichols, Miff Mole, Phil Napoleon, Joe Venuti, Eddie Lang, Adrian Rollini, Vic Berton, Benny Goodman, Jimmy Dorsey, Tommy Dorsey, Jack Teagarden and Irving Brodsky.
Hanshaw began appearing on the radio in 1929. In the early 1930s, she sang on the air with Glen Gray's Casa Loma Orchestra. From 1932 to 1934, she was featured on the popular Thursday evening radio program Maxwell House Show Boat. She made her only appearance on film in the 1933 Paramount short "Captain Henry's Radio Show", a "picturization" of program. Her music career ended on December 6, 1937, after a performance on "The Chevrolet Musical Moments Revue."
Hanshaw's singing style was relaxed and suited to the jazz-influenced pop music of the late 1920s and early 1930s. She combined the voice of an ingenue with the spirit of a flapper. She was known as "The Personality Girl", and her trademark was saying "That's all" in a cheery voice at the end of many of her records. Hanshaw had a low opinion of her voice, and she said was afraid of broadcasting. When asked why, she said, "I'm so afraid I'll fail, not sing my best. Suppose I should have to cough. Suppose I didn't get just the right pitch. And all those people listening." Hanshaw's favorite singers were Marion Harris, Sophie Tucker, and Blossom Seeley. She also enjoyed her contemporaries, Ruth Etting, Ethel Waters, and Connee Boswell.
She composed two songs, "Sweet One" and "Till Your Happiness Comes Along."
Hanshaw disliked show business. In a 1978 interview with Jack Cullen she said,
As a matter of fact, I disliked all of [my records] intensely. I was most unhappy when they were released. I just often cried because I thought they were so poor, mostly because of my work, but a great deal, I suppose, because of the recording. [...] I disliked the business intensely. I loathed it, and I'm ashamed to say I just did it for the money. I loved singing, you know, jamming with the musicians when it isn't important to do, but somehow or another I was terribly nervous when I sang. [...] You just have to be such a ham and love performing, and I happen to be an introvert, and I just wasn't happy singing, and I wasn't happy with my work as I said.
Hanshaw married Pathé Records executive Herman "Wally" Rose in 1929. In 1954, he died. She later married Herb Kurtin.
Later in life, in an attempted comeback, she recorded two demo records, "Penthouse Serenade" and "When I'm Housekeeping for You", but they were never released. She died of cancer in 1985 at New York Hospital, aged 83, after a long illness. She had been living in Manhattan. She had no children.
Collections of Hanshaw's recordings were released on CD by Sensation in 1999. Another revival of interest occurred in 2008 with the use of Hanshaw's music in the animated film Sita Sings the Blues, which retells the Indian epic poem the Ramayana from Sita's perspective by setting scenes from it to performances by Hanshaw. More recently, her 1929 song "Daddy Won't You Please Come Home" was featured in the video game BioShock 2 in 2010.
For many years it was believed that Hanshaw was born in 1910 and began her recording career shortly before her 16th birthday. However, it is now known that she was born nine years earlier, making her 25 at the time of her first commercial recording in September 1926. Her nephew, Frank W. Hanshaw III, confirmed that 1901 is the date on her birth certificate.