Once in a while it takes a bunch of courageous people to come up with something completely different even though it doesn't seem viable. The OP-1 is just such a thing. Looking like a toy and not like an instrument yet if you take a closer look it actually is. At first it reminded me of the Casio synths that were quite popular a century ago. Is the OP-1 the 21st century version of the Casio? Not really, but it takes some time to explain this because the answer is quite elaborate.