Croaky karaoke is so popular over in Japan that while video on demand may still be a dream for most people, karaoke on demand is already a reality. Sega Enterprises Ltd operates a karoake network, selling on-line karaoke service terminals that log into the network to get the tunes. Operated by Sega Music Networks Co Ltd, it had sold 10,000 systems by the end of August, and the concept and service is now to get a further fillip with capability being added to the karaoke terminals to access the personal computer on-line network service operated by NEC Corp in Japan next month. Users are to be able to operate a control device included with the karaoke system to get information from the network as well as songs.