Folk music icons Pete Seeger and Arlo Guthrie joined Occupy Wall Street marchers protesting corporate greed in singing the protest anthem \"We Shall Overcome.\"Also marching among the 1,000 people on Manhattan\'s Upper West Side were Seeger\'s folk musician grandson Tao Rodriguez-Seeger, composer David Amram and blues guitarist Guy Davis, marchers said.\"We Shall Overcome\" is a protest song that became a key anthem of the 1960s civil rights movement.The activists also sang the gospel song \"This Little Light of Mine\" as they marched 35 blocks Friday night to the landmark Columbus Circle, at the southwest corner of Central Park, a video of the march indicated.Seeger, 92, whose activism dates from the 1930s, is best known for writing \"Where Have All the Flowers Gone?\" \"If I Had a Hammer (The Hammer Song)\" and \"Turn, Turn, Turn!\"Guthrie\'s grandfather, Woody Guthrie, wrote \"This Land Is Your Land,\" which has become a popular refrain among Occupy protesters since Grammy Award-winning guitarist Tom Morello performed the song Oct. 13 in Zuccotti Park, the site of the New York Occupy encampment.