In doing research for my Phantom trilogy, I’ve gone down some interesting trails trying to get information on a specific detail, like whether a Paris police officer would have a six-shot gun (yes), whether the catacombs are actually under the Opera Garnier (no, but I’m putting them there anyway) and where Meg’s home village ought to be (near Toulouse). Bigger topics require more intensive research though, and I’ve read entire books on classical music, on 19th-century Parisians’ attitudes towards darkness and towards eccentricity, and on ballet.
The single most helpful book, however, has actually been a novel. It’s been remarkably difficult to find substantive information about the ballet program at the Opera Garnier in the 1880s. A lot of my information about the Opera Garnier itself has come from forwards in different copies of the Phantom of the Opera!
But I did have one wonderful find with regard to what life might actually have been like for Meg: Marie, Dancing by Carolyn Meyer, about the model for Degas’ famous statue, “Little Dancer Aged Fourteen.” Marie was a dancer at the Opera Garnier at exactly the same time as Meg, and the novel paints a more vivid and more substantive picture than any book or essay I’ve managed to find. I read it some six years ago, then read it again just in the last year, and it was incredibly helpful. Along with a general picture, she has details like how much money the dancers earned, which nights performances were held on, and the schedule for practice and rehearsals. Also, it’s just a good book!