There once was a time, some years before the ascendance of rock and roll on Top 40 radio, when popular music veered sharply from the mainstream to sample American roots-music traditions. Inspired by the songs of Pete Seeger and The Weavers, this “folk” music, found its greatest expression during the early 1960’s in the songs of an emerging Greenwich Village group known as Peter, Paul and Mary. In the Trio’s new PBS show “Carry It On: A Musical Legacy” we share in the four decade long career of Peter Yarrow, Noel Paul Stookey and Mary Travers. The Trio recalls the beginnings of the cultural revolution of the 1960’s when music emerged as a unifying force midst the hopeful, idealistic and sometimes turbulent, movements of social change. “Carry It On” features rare archival performances of songs that energized the spirit of the nation’s cultural and political renaissance. These performances include, “Blowin’ in the Wind” from the 1963 March on Washington where Dr. Martin Luther King Jr. delivered his legendary “I Have a Dream Speech”, “The Times They Are a Changin” sung at the Newport Folk Festival of 1964, and their first televised performance of their breakout hit song, “Lemon Tree”.