ON MySpace carving out a virtual niche of your own takes a few clicks of a mouse. In the real world the job never ends. As classical divas at the head of the class Cecilia Bartoli and Renée Fleming share native talent, personal glamour, a puritan work ethic, a capacity for self-criticism and also something extra: a scholar’s taste for intellectual adventure.

Long evident in their discographies, these attributes shine again in their latest recordings, both for Decca. Ms. Fleming’s “Verismo” and Ms. Bartoli’s “Sacrificium” are like graduate seminars dressed up as recitals.

Ms. Fleming, 50, recalls the advice given her by Herbert Breslin, who masterminded Luciano Pavarotti’s career. “ ‘You won’t make it if you don’t sing bread-and-butter Italian opera,’ he told me,” Ms. Fleming said in a recent telephone interview. “I was constantly being pushed toward a European ideal of what it means to be a classical or opera singer, let’s say in the Renata Tebaldi mode. I reject that. I’m American. I’m eclectic. I’m going to follow my musical passions. And if people don’t like it, and it hurts my legacy, I’m not going to worry about that.”

The late 19th century and the first quarter of the 20th have proved particularly congenial to Ms. Fleming’s gifts. In 2006 she surveyed that period on “Homage: The Age of the Diva,” recorded in St. Petersburg, Russia, with Valery Gergiev leading the Orchestra of the Maryinsky Theater. Inspired by historic recordings of stars like Mary Garden, Maria Jeritza, Rosa Ponselle, Emmy Destinn and Lotte Lehmann, the program included a sprinkling of favorites among a spate of rediscoveries.