Enrico Caruso
From Memory Alpha, the free Star Trek reference.
Enrico Caruso was a male Human opera singer in the late 19th and early 20th century. Among his performances was La bohème with Amelita Galli-Curci.
The Doctor studied recordings of his and Galli-Curci's La bohème while trying to improve his own performance in 2373. (VOY: "The Swarm")
