Pandora, the world's largest internet radio service, is giving musicians free access to the data it stores about their biggest fans.

Pandora, which reports third-quarter results on Oct. 23, already uses the listener data for advertising purposes. It has helped political candidates decide where to advertise for the upcoming election.

Starting today, the more than 125,000 artists on Pandora will be able to view detailed information about their songs' popularity, breakdowns of the audience based on age and gender, and a map that shows where listeners are located. The data can be used to plan tour and set lists and better target fans, Pandora said in a blog post.

"We hope to make the day in and day out easier for artists by eliminating the guesswork," Pandora founder Tim Westergren wrote on the blog. "Our ultimate goal is to help artists across the spectrum build and maintain their careers."

Pandora, which has more than 76 million active users, has amassed a trove of information over the past nine years. It wants to use that data to improve its contentious relationship with the music industry, which has long sought more money from the Oakland, California-based company.

The company in the last two months has reached agreements to license music from rights management groups BMG and Merlin, which collect fees on behalf of artists. The company said in those deals it would share its data with musicians.

With the Artist Marketing Platform announced today, musicians can log in and find out how many people are listening to their songs, how many people have created a new station based on a song and how many listeners they have in total.

The data can help artists decide where to stop on a tour, decide what songs to play and pick their next single, Mr. Westergren wrote.

~ Bloomberg News ~