An increasing amount of Japanese pop music of late is eschewing vocal cords for Vocaloid, a series of voice synthesizers developed by Yamaha that is designed to fill the role of human singers. The most famous of these is Hatsune Miku, which (who?) has an image and persona more visible than many "real" Japanese stars, though it's otherwise quite a niche phenomenon. One problem with Vocaloid tracks is the difficulty of authentic live performances, but Yamaha is working on something to combat this — a real-time Vocaloid keyboard that allows players to "sing" syllable by syllable.
The keyboard is made possible by the relative simplicity of Japanese phonology, with only fifty or so possible syllables in the language altogether. Syllables are selected by simultaneously pressing a Roman alphabet key with a D-pad-shape modifier for one of the five Japanese vowels — so, for example the "K" key with an "A" directional press would result in a "KA" consonant. This is all done with the left hand, with the right hand controlling each syllable's pitch via a standard keyboard layout, and there's an LED display to confirm character input. The interface seems simple and logical for Japanese speakers, though it will take some practice to get right — Yamaha says that several players so far have been able to play nursery rhymes after around three hours with the device.
The keyboard is still in development with no solid plans for a commercial release, and the prototype still looks pretty rough from a design standpoint. The company says it's more likely that it would provide the sound chip inside for other companies to use in their own hardware. However, if a product ever sees the light of day it could well be the next step along the way to Vocaloid domination of J-pop.