Romans were particularly concerned by ‘prodigies’, odd things and events which seemed to be signs of the gods’ communication. A prodigy might be a deformed child at birth, a mole (reportedly) with teeth or an apparent shower of blood from heaven. Soothsayers and a priest stood by to list prodigies and interpret them.

- p. 299, The Classical World, Robin Lane Fox

Wiktionary has prodigy coming via Middle English prodige (“portent”), from Latin prodigium (“omen, portent, prophetic sign”).

Because of the phrase “child prodigy”, I grew up assuming that “prodigy” meant “gifted person”. Later, I think I must have seen it used in the sense of “prodigious feat”, which probably reinforced my belief.

It’s a neat little revelation. Normally, a gifted musician puts me in mind of the thousands of hours of work they’ve spent polishing whatever natural talent they began with. But the concept of “prodigy” jolts me into a world-view in which a musician’s talent can only be understood as an omen from the gods.

Also, the idea that a prodigy can be either a blessing or a curse for the messenger sets me reeling a bit.

“Messenger” is the wrong word, I think. If there’s a consciousness involved (a deformed child, say), then they’re more the slate on which the message is written than an active messenger; even a phenomenon (e.g. blood falling as rain) can serve as a prodigy.

I like the name “The Prodigy” a lot more now, even though this article says it’s taken from the Moog Prodigy synthesizer.