In honor of Presidents' Weekend, we will join together in anthems and folks songs from the eras of George, Abe, Teddy, Franklin, Jack, and Barack (and others). Happy days are here again, as are melodies from the labor, suffrage, peace, and civil rights movements, traditional spirituals, campaign ditties, and political show tunes. Bring instruments, iPhones (to search for songs and lyrics), ideas for songs you want to sing, and your sonorous voices.