See the banjo pictured above? Seeger's banjo said, "This machine surrounds hate and forces it to surrender". This is a more beautiful and peaceful variation on what his mentor Woody Guthrie's guitar said: "This machine kills fascists."
Did you know that Pete Seeger was a Unitarian Universalist? Obviously this was just one part of his life; I'm not sure how active he was. Seeger's mother, apparently, was briefly a Unitarian (before the UU merger). And he himself joined the Community Church of New York later in his life (that's a UU congregation). Apparently he originally went there as a renter, needing a place to rehearse some singers. He did perform at some UUA functions over the years.