So.
What if you had a guitar that dropped that chamber altogether but retained the piezo pickup and all the other attributes of an acoustic? You'd end up with something like this Yamaha:

I recently traded an electric guitar and an amp I wasn't using to obtain one of these, and I'm quite pleased. I play an acoustic mini-set (3 songs) most every week at a local open mic and, not only does the guitar draw comment on the looks, but also many compliments on the sweet tone. It's got the usual addons you see on acoustics with pickups: bass and treble, volume, a tuner...and it also has a control that lets you add in either chorus or reverb.
Another virtue (and the reason it's called the Silent Guitar) is that I can practice with it late at night and make no appreciable sound. It has a headphones jack for such times (or I can plug phones into my acoustic guitar amp).
I haven't given her a name yet, for now she's just my Air Guitar. :silly: