Haran appeared on Broadway in The 1940s Radio Hour and appeared Off-Broadway in Manhattan Music, Swingtime Canteen and Heebie Jeebies.
She was perhaps best known for her work in cabaret, having performed numerous shows at such venues as the Russian Tea Room, Rainbow & Stars, the Ballroom, the Oak Room at the Algonquin Hotel, the Cafe Carlyle, and Feinstein's at the Loews Regency. She also appeared as part of the 92nd Street Y's Lyrics & Lyricists series.
Haran co-produced and wrote the PBS documentary, Doris Day: Sentimental Journey and contributed to many other PBS documentaries.
She made numerous recordings throughout her career, including There's a Small Hotel: Live at the Algonquin, This Funny World: Mary Cleere Haran Sings Lyrics by Hart, This Heart of Mine: Classic Movie Songs of the Forties, Pennies From Heaven: Movie Songs From the Depression Era, The Memory of All That: Gershwin Broadway and in Hollywood, and Crazy Rhythm: Manhattan in the 20s.
She is survived by her son, Jacob Gilford, her stepmother, Loyce Haran, and six siblings.