It must be a running bet among some bored developers, a game to see who can come up with the weirdest musical instument that can be folded away. That's the only way we would even attempt to guess how something like a canned piano was created.
This invention of the absurd has its limits, unable to play sharps or flats, but Japan's Strapya has priced it right at only $8.90, according to Plastic Bamboo. We've encountered other roll-up keyboards and have seen the concept applied to other instruments, including virtual drums. But a can? With a picture of a duck on it?
Come to think of it, maybe there's a more plausable explanation after all.