Catherine Lynn Steele was born in Beaumont, Texas on May 27, 1951. Her family moved to Massachusetts while she was still young, and she lived along the eastern seaboard for most of her life. At around the age of 9, she began composing, finding it, as she once said "more fun than practicing the piano". Her first work to be performed was Conglomera, premiered by her Junior High School Orchestra in Hingham, MA in 1964. Her juvenilia from around this time includes numerous songs from ambitious and elaborately planned musical theatre projects some of which even include maps and drawings of the sets required.
She attended Smith College from 1969 to 1973 and majored in Spanish, but continued to pursue music, taking composition lessons from Alvin Etler, as well as voice lessons. After graduating she spent a year teaching elementary school music in Ipswich, Massachusetts and another abroad at the Monterey Institute, studying to be a translator - a skill which she applied to song texts as well as other works in German, Swedish, Spanish, Portuguese, and other languages. In 1977 she began working at the American University in Washington, DC, and taking classes, part time as a composition major, studying with Jerzy Sapiyevski. She received her masters degree in 1982, having completed a full length opera, Dominique, which was performed on April 23. She remained in Washington promoting her music and singing in concerts while making a living at various secretarial jobs. It was during this time in 1983 that she published her first piece Carrillon de Nuit, which was performed by the Memorial Ringers of which she was also a member.
Steele played a number of instruments, and was active in the early music ensembles at the University of Cincinnati College-Conservatory of Music, where she began her doctoral work in 1986. She worked a number of years as a teaching assistant there while studying with Jonathan Kramer and Allan Sapp. In 1989 she moved to the Boston area and returned to office work, this time at the Sloan School of Management at MIT; she continued her interest in early music at the Longy School of Music. She was active in the American Women Composers of Massachusetts, even serving as that organization's vice-president in 1993 and then as president in from 1993 to 1996. After receiving her doctoral degree, in 1993, however, her interests slowly turned more towards singing than composing although her works were still performed - both by herself and by others. One of her main interests was in Scandinavian composers and art song, which she traveled to Sweden to study in the summer of 1999. She had been diagnosed with cancer, yet remained a vibrant and active personality, giving concerts and remaining active as a musician until her death on December 10, 2002.