Aging pop stars Elton John and Billy Joel will combine into one artist, tentatively named 'Billy John,' record industry executives announced Monday. The two stars' identical baby-boomer audience, as well as the similarities in their inoffensive, adult-oriented songwriting style, were cited as reasons for the change. 'Face it, in today's market, there's just less and less room for more than one artist in this niche,' Billy John spokesperson Sol Herberger said. A computer-generated image combining the two singers into one person has already been signed as the new spokesman for Coke, and a deluxe box set will be released this December. If the merger is successful, additional pop mergers have been planned, including a combination of Eric Clapton and Phil Collins. 