The subject of John Singer Sargent's most famous painting was 23-year-old New Orleans Creole Virginie Gautreau, who moved to Paris and quickly became the ''it girl'' of her day. A relative unknown at the time, Sargent won the commission to paint her; the two must have recognized in each other a like-minded hunger for fame. Unveiled at the 1884 Paris Salon, Gautreau's portrait generated the attention she craved-but it led to infamy rather than stardom. Sargent had painted one strap of Gautreau's dress dangling from her shoulder, suggesting either the prelude to or the aftermath of sex. Paperback, 320 pages.