US pianist Roger Williams, who topped the Billboard charts in the 1950s with his solo performance of Autumn Leaves, has died in Los Angeles aged 87.Williams, the only performer to have a US number one with a piano solo, had been suffering from pancreatic cancer.The musician was known as \"the pianist to the presidents\", having performed for US leaders from Harry Truman to George W Bush.Ex-First Lady Nancy Regan called him \"a great pianist and a great American\".Williams, who was the first pianist to be honoured with a star on Hollywood\'s Walk of Fame, was well known for playing 12-hour piano-playing marathons, including on his 75th birthday at New York\'s Steinway Hall.Following his 1955 chart-topper, the popular musician also scored hits with piano renditions of the themes to Born Free and Dr Zhivago, and became a regular guest on TV programmes including The Ed Sullivan Show.His final concert came in March, just days after announcing his diagnosis of cancer.In an interview in 1995, Williams said that he liked listening to and playing all genres of music.\"The only thing I have against rock\'n\'roll is the volume,\" he said.