James McNeill Whistler

American expatriate who spent his career in London and Paris arguing that painting should be judged like music — as an arrangement of tones, not a story. He gave many of his canvases musical titles (Nocturne, Symphony, Arrangement) to make the point. A famously combative figure, he sued the critic John Ruskin for libel after Ruskin called his Nocturne in Black and Gold a 'pot of paint flung in the public's face' — and won the case for a single farthing. His emphasis on mood and surface over subject was an early step toward 20th-century abstraction.