Billboard chimes in on ring tones

The music industry magazine will soon be publishing a list of best-selling ring tones, alongside its more traditional categories, like best-selling album.

The new listing, which debuts in the Nov. 6 issue, reflects the "growth, innovation and success of the rapidly growing mobile music market," Billboard said in a statement Tuesday. The "Hot Ringtones" chart will list the top 20 selling ring tones for each week. It will be based on sales of polyphonic, or "real music," ring tones compiled primary from U.S.-based providers, Billboard said.

Ring tones, which were introduced about three years ago in the United States, have grown increasingly sophisticated. Sales are increasing 20 percent to 30 percent every three months and are expected to reach a record $250 million this year, according to recording industry sources. Billboard and the CTIA, a cell phone trade group, estimated Tuesday that ring tone sales will be higher this year--about $300 million.

Once limited to just nine different musical tones playing one after another, ring tones now feature complex harmonies and any number of different sounds. In the future, it's expected that ring tones will be accompanied by graphics.

Ring tones are among the biggest hits in the market for cell phone services and content.

The wireless data market currently represents about 5 percent of annual revenue for a carrier. Wireless operators expect that the figure will ultimately grow to 20 percent and help offset plunging revenue from voice calls, still a carrier's primary product.