You thought of this invention yourself, sure you did. We all did. But we didn't go off and actually build one - that would be insane. But someone did, and so it's become just
one of a great collection from the Oddmusic Musical Instrument Gallery.
To sound this instrument, actual air is blown across actual beer bottles filled to different levels to produce the different notes. Unfortunately the bottles are filled with mineral oil, and not beer, which would evaporate too quickly. (Yeah, that's what happens, the beer evaporates. Really quickly, too. It's a mystery.)
You can even sample "Eleanor Rigby" at the link, and it sounds about like you'd expect it to sound. Clearly they need some pony bottles for the high end, some 40 ouncers to fill out the baritone, and some magnums for more bass.