An idiosyncratic songwriter who wrote folk songs from a unique, often insightful perspective, Williams took pains to avoid the coy and the quirky; her songwriting and performing style have been compared to those of Joni Mitchell and Joan Baez, but with a few acidic and at times hilarious twists. She was born in Mount Kisco, New York, but raised in Chappaqua, the daughter of medical writer/editor Gray Williams and Marian Ferry, an active figure in Planned Parenthood. Her parents were educated at Yale and Vassar, respectively. Raised in a decidedly liberal arts atmosphere, Williams began studying guitar at age nine and wrote her first song at 11. In high school she was interested in athletics, but an ankle injury led her to audition for the musical Godspell. She became active in drama, and by her senior year, after composing more music and writing plays, considered herself a playwright. She blames an "existential crisis" at age 16 for her creativity and sharp sense of humor.

During her sophomore year at Wesleyan University in Connecticut, Williams spent a few months in Berkeley, California, where she wrote songs and performed at the Starry Plough. After earning a B.A., she moved to Boston in 1990 to find a career in the arts, dabbling in everything from directing plays and operas to performing. By the year's end she was stage manager for the Opera Company of Boston. She also began taking voice lessons and it was her teacher, Jeannie Diva, who encouraged her to try the coffeehouse circuit. Williams tried hard, especially between late 1992 and early 1993, but things didn't pan out, so she abandoned Boston for the relaxed, folksy, artsy atmosphere of Northampton, Massachusetts, home of many prominent universities.

Williams claimed to draw much inspiration from her home community. Her love of the folk scene stemmed from her admiration of its integrity toward honesty and real emotion, and a creative freedom not found in more popular music genres. She loved trying to use traditional methods to express the realities and foibles of contemporary life. After several self-released cassettes, Williams made her proper debut in 1993 with the independent Honesty Room to considerable critical acclaim for both her beautiful soprano voice and her lovely, intriguing songs. The following year she signed to Razor & Tie Records, which reissued the album. Her second album, Mortal City (1995), was similarly praised, and was followed by 1997's End of the Summer.

Williams performed on the college and coffeehouse circuit and won rave reviews for her festival appearances, including the Newport Folk Festival and the Mississippi River Music Fest, St. Louis. She issued Cry Cry Cry as part of the folk trio of the same name in 1998, and her own The Green World followed two years later. Over the next few years, Williams remained a major presence on the concert trail; she also recorded songs during a two-year trek across America and Europe. She hooked up with Alison Krauss, Béla Fleck, Dave Matthews Band's Stefan Lessard, trumpet player Chris Botti, and others for the impressive The Beauty of the Rain, which appeared in February 2003. My Better Self, Williams' most personal set of her career yet, arrived two years later, followed by Promised Land in 2008. In 2010, Williams released the career-spanning two-disc set Many Great Companions, which features one compilation disc of fan favorites and another disc of newly recorded songs from her catalog performed in an acoustic format. Williams' ninth studio project, In the Time of the Gods, appeared in 2012 from Razor & Tie.

Having established a loyal fan base over the prior two decades, when her contract with Razor & Tie ran out, Williams decided to try a D.I.Y. approach to her tenth studio album, Emerald, crowd-funding before signing with UK label Bread & Butter shortly before its release in the spring of 2015. Inspired by collaborations and long-term friendships, the album featured an impressive lineup of guests including Richard Thompson, Jim Lauderdale, Jill Sobule, the Milk Carton Kids, Lucy Wainwright Roche, and Angel Snow. ~ Sandra Brennan