MacArthur's earliest exposure to the oral tradition came through the nursery rhymes that her mother sang to her and the cowboy songs that her stepfather, a forest ranger, sang as she was growing up in Arizona and the Ozark Mountains of Missouri.

After marrying and moving to Vermont in 1948, MacArthur lived a simple, rural life in a cabin home that had no electricity or running water. MacArthur's involvement with folk music began when she volunteered to teach music at the school that her children -- Don, Gary and Megan -- attended. By 1951, MacArthur was a regular performer on local radio stations. Her debut album, Folk Songs of Vermont, was released in 1961. MacArthur subsequently focused on the traditional songs and stories of the Green Mountain State on her albums Almanac of New England Farm Songs (1982), Vermont Ballads and Broadsides (1989), and Vermont Heritage Songs (1994).

MacArthur's 1976 album The Old Songs featured backup vocals and guitar accompaniment by Maine-based folk singer Gordon Bok. MacArthur was accompanied on four albums -- Make the Wildwoods Ring, MacArthur Road, On the Mountain High and Them Stars -- by members of her family.

In 1990 and 1991, MacArthur served as artist-in-residence under the auspices of the Vermont Council of the Arts. A book, written with help from students of 21 schools, The Vermont Heritage Songbook, was published in 1992.