She released her first solo album, Visions and Dreams, in 1991.
In 2003, her song "I Should've Known Better" appeared on Nickel Creek's album This Side.
In 2007, Newcomer collaborated with fellow Quaker author Parker J. Palmer co-writing the song “Two Toasts” for her album The Geography of Light which received the Artist of the Year and Album of the Year awards from Folk Wax Magazine. That same year she wrote the theme song for the national organization of the YMCAIn 2007, she collaborated with Scott Russell Sanders and folk songwriters Krista Detor, Tim Grimm, Michael White and Tom Roznoski to create an album and theatrical production entitled Wilderness Plots, based on songs inspired by the short stories of Scott Russell Sanders about the history and settlement of the Ohio Valley.
In 2008 Boston's WUMB included her on a list of the Top Most Influential Artists of the past 25 Years. 
In 2009 Newcomer toured throughout the country of India as a cultural ambassador for The American Center, the cultural outreach division of the American Embassy located in India. While in India, Newcomer performed concerts, visited community service projects and facilitated workshops. She collaborated with author Jill Bolte Taylor to create the presentation "Transforming Stories."
Her album Before and After was released in February 2010.
Newcomer also participates in songwriting workshops, creative writing, activism and the arts