"The idea is that consumers can download as many songs as they want," Mr. Ryan said, "and move them from one device to others, but at the end of 30 days, if you don't pay the subscription fee, the songs go away.

While the technology exists to offer such a service, Mr. Ryan said there were a number of issues to work out, including how much to charge. "But I think we'll see such a service by the end of next year."

"And that's where this gets interesting," he added. "You've got a portable music player that can fit 10,000 songs on it? Come on. No one will spend $1 a track filling it.'' [NY Times] I would nod sagely and add, "No shit."

But portable players, he said, "become totally useful'' when it is possible to rent an unlimited number of tracks for a flat fee. Mr. Ryan and other executives said consumers would also enjoy a greater range of tracks next year, as the download sites expand beyond pop music, and as artists migrate toward a growing revenue opportunity. Classical and jazz tracks will begin to proliferate, and Mr. Ryan said, live, archived performances from popular musicians will see new life online.

....Music owners will also have more flexibility in what to do with the tracks they download, said John Rose, executive vice president of EMI.

"Two or three years out, I'll be able to send you an album that you can listen to once or twice, but that will expire after a certain amount of time if you don't buy it," Mr. Rose said. "The technologies are all starting to percolate. We'll start to see much more of that come to market in the next year."