The Doctor

In the "Virtuoso" episode (January 26, 2000) of sci-fi TV series Star Trek: Voyager, the on board Emergency Medical Hologram, known simply as "the Doctor," sings for the amusement of advanced alien race the Qomar, whose leader is played by real singer Paul Williams.

Never having the concept of music, the Qomar become enthralled by his singing, and want him to stay on their planet. The Doctor, suffering from sitcom disease "big head syndrome," wants to leave, despite his duties on the ship. He even wants to delete his medical knowledge to free up space to increase his vocal range!

It all turns moot when the Qomar simply duplicate his hologram, drop the medical stuff, and boost the singing range into multiple octaves. The original Doctor is no longer wanted, and stays with The Voyager.