The Mellotron is a keyboard hooked up to analog tape. Press a key and the instrument plays a corresponding section of sound on the tape. It's the original sampler, popularized by the Beatles, the Moody Blues and a handful of other bands in the 1960s and '70s.
And now, it's back with a modern twist. The Crudman, from Brooklyn's Crudlabs, isn't exactly a Mellotron, but it operates similarly by connecting a keyboard to a hacked Walkman. You could even call them polyphonic sprees, if you're feeling saucy.