We think that we live in a celebrity-obsessed age, but, as it turns out, we have nothing on the nineteenth century. Among the nineteenth century’s many stars, Fanny (1809–93) and Adelaide Kemble (1814–79) were the ultimate A-listers. In their long, complicated, and rivalrous lives, they embodied the competition between words and music that forms the governing conceit of Strauss’s Capriccio. Born into England’s foremost theatrical family—some would say that their aunt, the regal Mrs. Siddons, was even more of a luminary than they—Fanny was one of the most acclaimed actresses of her day while Adelaide was a distinguished mezzo-soprano.

Both sisters extended their renown well beyond the confines of England: Fanny was as much a phenomenon in the United States as in her native country; Adelaide performed regularly on the continent. Yet both their professional careers were brief: Fanny retired from the stage at twenty-four, after less than five years on the boards, returning only in later life to give a series of popular Shakespeare readings. Adelaide ended her public performances after roughly four years. Both withdrew to become the wives of wealthy men. As Kembles, however, they dined out famously before, during, and long after their time on stage. And, with the panache befitting a Kemble, Fanny contrived to keep herself in the public eye by writing about it all.

In an age in which the theater was still regarded as louche or worse—French actors were refused the last rites and could not be buried