Levon Helm, drummer and singer for the Band, died yesterday from complications of cancer. He was 71. Helm is best remembered as the sole American in the otherwise Canadian group that became Bob Dylan’s backup band and later, simply “The Band.” In the past decade, he gained a reputation as a roots-music patriarch, hosting a series of concerts called “Midnight Rambles” in his Woodstock barn. Songwriter, producer, and Grammy Award-winning musician John Leventhal played with Levon in the 1980s. He remembers a charismatic performer who was often like a character in one of his own songs.