(FORTUNE Magazine) – It started as an annoying mobile-phone ring tone. Then it inspired an irritating hit single. Now the Crazy Frog--it is both a ring tone and a video for cellphones marketed by VeriSign's Jamster unit--has spawned an entire CD that mixes croaks and cackles with tunes such as the Beverly Hills Cop theme "Axel F," which hit No. 1 on the U.K. charts.

Talk about the tail wagging the frog. In recent years music companies have made big money licensing their songs for ring tones, but this is the first time a ring tone has been turned into a bona fide hit song. It's certainly not the last, however. Next Plateau Entertainment, which co-produced the Crazy Frog CD, is hiring artists to develop 20-second hooks and choruses suitable for the ring-tone market--with the aim of turning the most popular ones into full-length tracks. "The music industry introduces talent via radio, videos, touring," says Next Plateau president Eddie O'Loughlin. "Why not cellphones?" Crazy indeed. -- Stephanie N. Mehta