Made obvious in several scenes in this episode (and The Swarm (1996), for that matter), Robert Picardo, the Doctor, is an
accomplished singer. While he was at Yale University, he was a member of the Society of Orpheus and Bacchus, the second longest
running undergraduate a Capella group in the United States. Then in 1977, he made his Broadway debut. He appeared in Gemini (1977) and Tribute (1980).
The aria sung by The Doctor in his final Qomar performance is "Rondine al nido," by Italian composer Vincenzo De Crescenzo. Voice over was provided by tenor Agostino Castagnola.
The Doctor, when arguing with Janeway about his request to leave Voyager, cites his artificial nature as an example of Janeway's potential bias, stating, "If Harry Kim met an alien woman on an away mission, fell in love and decided to spend the rest of his life with her, raise a family instead of continuing on this journey, you wouldn't stand in his way." As a matter of fact, this is almost exactly what happened to Harry Kim in The Disease (1999), and Janeway in fact did stand in his way in that instance.
The appearance of songwriter Paul Williams in this episode is a little ironic, as his character is from a race that does not know what music is.
Lieutenant Torres tells the doctor "I'm an engineer, not a costume designer" as an obvious nod to the original Star Trek (1966) when Doctor McCoy states, often, "I'm a doctor not a..."