The bar inches across the screen as the number of transferred bytes slowly ticks up. You can almost hear the song blaring out of the speakers. But then the three most hated words in any song downloader’s vocabulary — “more sources needed” — appear on the screen.

The connection is lost and so is the free download.

For now, users of new pay-per-download music download sites such as Apple’s iTunes and Napster 2.0 do not have to worry about this scenario. While Yale’s Information Technology Services will continue to monitor the situation, the University is not currently slowing inbound or outbound connections for these programs, Joe Paolillo, director of data network operations for ITS, said Wednesday.

Paolillo said ITS limits the rate of inbound and outbound traffic for no-cost filesharing programs such as Audiogalaxy, Gnutella, iMesh and KaZaa to prevent users of these programs from “swamping” Yale’s Internet connection. Paolillo said ITS limits each inbound “flow” or session to 50 thousand bits per second.

“Is it going slower than if we had no limits? Sure. But you’re getting [your downloads] in a reasonable amount of time,” Paolillo said. “The issue is that, unfettered, one machine can consume a lot of bandwidth.”

Use of the outbound connection — the connection to non-Yale computers — was especially bad before ITS slowed no-cost filesharing programs’ connections, Paolillo said, because these programs track reliable song sources and connection speeds. Yale’s network met both criteria.

“We were really almost swamping the link,” Paolillo said.

ITS has limited outbound no-cost program traffic to 1 million bits per second per application. There are no limits on connection speeds for filesharing within the Yale network.

One major difference between iTunes and the no-cost programs is that while iTunes allows users to share music on a network, no one other than the song-purchasing “owner” may actually save a copy. This means that when the “owner” of the song signs off the network, other parties can no longer access it.

But a student at Trinity College found a way around this block. Trinity sophomore Bill Zeller, 20, created the companion program myTunes 10 days after Apple released the Windows-compatible version of iTunes.

“I didn’t sleep [during those 10 days],” Zeller joked.

Zeller said his program allows users to save shared song files to their hard drives.

Between 700 and 800 people a day have been visiting his Web site for the past few days, Zeller said. He said in the first five days of November he had already used up half of his allotted bandwidth for the month.

Zeller said no one from Apple has contacted him yet. There are four or five Macintosh-compatible programs that serve the same function as myTunes, Zeller said.

While Zeller has developed a new way of using software, students at the Massachusetts Institute of Technology have created an entirely new way of sharing music.

According to an MIT press release, the Library Access to Music Project uses the university’s cable television system to provide students with access to 3,500 CDs that can be played through their televisions or stereos.

MIT graduate student Keith Winstein, 22, who helped create the project, said in the release that it would cost about $35,000 in startup costs for another university to copy the system. The project has been temporarily suspended due to licensing concerns.