Promising to become the C-SPAN of jazz music, WorldJazz Inc. will start a 24 -hour TV channel devoted exclusively to the popular genre.The new channel, WorldJazz, will begin broadcasting simultaneously in the U.S. and Japan in September, featuring programming of live concerts, interviews and other longform programs. “Jazz music is a uniquely American art form that has a wide appreciation around the world,” said Brian L. McCarty, founder and chairman of WorldJazz, a subsidiary of Green Dolphin Media, a Pasadena-based broadcasting consulting firm. The channel “will not imitate other music-oriented formats, but, in keeping with the jazz style, we will aspire to be the C-SPAN of jazz,” he said. The network will be carried by both cable and direct broadcast satellite systems. The company also is negotiating for more than 11,000 hours of jazz programming produced by PBS and PBS member stations. WorldJazz has pacted with Clipping Point K.K., a subsidiary of Matsukami Corp. a Japanese communications consortium. The company also expects to announce a European partner in the near future.