Hildegarde was 99. Her longtime friend and manager Don Dellair told AP that the entertainer died at New York-Presbyterian/Weill Cornell Hospital.

The singer was born Hildegarde Loretta Sell in Adell and later raised in Holstein, Wisconsin. Her father was a merchant who also played the fiddle and the drums, and her mother played the organ and also directed the local church's choir. Although Hildegarde's first desire was to become a concert pianist, circumstances prevented her from finishing her work at the School of Music at Marquette University.

Hildegarde eventually found work on the vaudeville circuit, where she was discovered by Gus Edwards. After touring the country in a travelling show, Hildegarde played Paris, London, Cannes and Brussels, but it was in New York where she became the toast of the cabaret world.

During the 1930's and 40's she was often booked into clubs 45 weeks a year, and her recordings sold in the hundreds of thousands. Hildegarde even graced the cover of Life Magazine in 1939. She also appeared in television specials and toured with the national company of Stephen Sondheim's Follies.

We may now have Cher and Madonna, but Hildegarde was the first entertainer to become known by a single name. The performer accompanied herself on piano and often poked fun at herself between songs. During a performance at the Algonquin Hotel in 1993, AP reports the singer joked, "Wrinkle, wrinkle, leave me alone. Go and sliver Sharon Stone."