Not as crazy as most, in fact I think it'd rather work well.
Simple enough concept; take a theremin to start with, great base idea but it kind of... yeah the sound is just wrong. I figure it should be possible to take a sample library, normally used for synths, and set it to essentially play a vocal choir instead of it's whiny high pitched squeal of a sound. Would possibly just need to build something similar to an effects pedal for an electric guitar... or it may be more complex and require building a large rig to attach to a computer, no idea.
Maybe then people would finally start taking the instrument seriously, if it didn't sound like it escaped from a b-rated sci fi movie. (which it's sadly actually been used for those...)
While the instrument's perfect for replicating such a sound convincingly, due to how it's played... I have absolutely no clue how to go about making the adjustments sadly, and don't have the attention span to bother. Maybe someday someone'll read this who does know how and will make use of the idea. But probably not. Oh well.
If only I knew more of the technical details on how to make that work, or wasn't quite so lethargic as to not care XD