Jem Aswad Senior Music EditorSylvain Sylvain, cofounder and rhythm guitarist of legendary early 1970s proto-punk quintet the New York Dolls, has died after a battle with cancer, according to a social media post by his wife and multiple media reports. He was 69.While often lambasted in their era — either as Rolling Stones knock-offs or for their shocking-at-the-time androgynous look — the Dolls were one of the key influences on punk rock, on both sides of the Atlantic.