The American Society of Composers, Authors and Publishers (ASCAP), the largest organization that protects the rights and royalties of songwriters and composers, yesterday announced a license agreement with a major music Web site, MP3.com. The deal allows the site to broadcast performances of any of the more than 4 million songs in ASCAP's catalogue--many of the pop music hits of the last several decades.

The arrangement lets MP3.com act as a radio station, but not a record store: Visitors to the site will be able to listen to digital versions of songs that are "streamed" to their computers, but they won't be able to store them for later playback. It's one of the first times that a major player in the music industry has agreed to work with the site, which gives away copies of songs in the popular but controversial MP3 digital-music format.

"It's our business to find out where music is being performed, and to make sure that it's properly licensed," ASCAP vice president of marketing Phil Crosland said yesterday. "Until now, they didn't have that license."

Now, however, MP3.com's artists--many of whom lack any record deal at all--will be able to cover songs in ASCAP's repertory and transmit those versions via the popular Web site. A folk singer in Boston or a go-go band in the District could attract listeners with an interpretation of a hit song, the same way that a new band will often spend much of its time onstage on other people's songs.

MP3.com will then provide ASCAP with information about the songs that are being played and how many times they are played; ASCAP will make payments to the songwriters based on this data. Crosland declined to disclose the fee that would be collected from MP3.com, citing ASCAP policy, but said license fees for Web sites range from $250 to $200,000 a year.

Crosland said that while ASCAP started the conversation, both sides benefit. "We share those two important objectives: protecting creators' rights and developing musical talents." He said that MP3.com will promote ASCAP membership to songwriters distributing music through the site, while "we're also going to direct our members . . . to the offerings of MP3.com."

MP3.com has been at the center of a controversy over the protection of the rights of musicians and record labels. Many powerful interests in the recording industry have claimed that the availability of songs as easy-to-transfer, free-to-copy MP3 files on the Internet fosters piracy of copyrighted material. While all of the files on MP3.com have been put there by musicians looking for exposure, the format is widely used elsewhere on the Internet to distribute or obtain pirated copies of songs.

MP3.com and other music Web sites have countered that the free transmission of music on the Web is a natural outgrowth of new technologies. The MP3.com license with ASCAP is an attempt to bridge the traditional legal aspects of copyrights and royalties and the newfound proliferation of free music on the Web.

It is not the first ASCAP blanket license to go to a Web site. Crosland said the group has negotiated deals with "over a thousand sites," including such popular Web destinations as Broadcast.com. But it does affect one of the most frequently used destinations for music on the Web and comes at a time when the music industry as a whole is struggling to determine how the Internet can be used as a business tool for supplying music to the public.

"We are trying to reach the broadest group of musical talent, help them reach their audience and protect their rights," said Ron Sobel, ASCAP's assistant vice president and director of repertoire. "We are putting profits into songwriters' pockets."

The transmission of popular songs on MP3.com would deviate from MP3.com's usual process of allowing people to download audio files as "MP3s," compressed files that can squeeze a three-minute song into about four megabytes of computer data.

The ASCAP-covered music will be "streamed" to the listener, meaning the Web surfer will be able to hear songs on demand but will not be able to save them directly to a disk. For artists to give away or sell complete recordings of other people's songs--as opposed to playing them live or broadcasting them over the air or online--they would need to negotiate a separate license, something that ASCAP isn't involved in.

ASCAP and MP3.com also said they would co-host workshops for musicians. The workshops would be held online and in live venues. Michael Robertson, president of MP3.com, refused to comment on the licensing agreement, even though ASCAP made the announcement at a Web music conference that his company was hosting. His company is attempting to sell stock to the public, and federal laws restrict the statements a company can make before the stock goes public.