The company posted an appeal for beta testers on its Web site Wednesday, saying it is looking for people to be "the first to preview the new membership service." No further details were available.
A representative said the subscription service is still scheduled for a summer launch but that no hard date has been set. Executives from Napster and Bertelsmann, the music-swapping service's partner in the venture, previously said they expect a July launch.
The call for testers is one of the first tangible signs of life from the proposed subscription service, which has so far met with stony skepticism from record labels approached by Napster to participate.
As outlined, the service would be much like the original Napster, with members able to swap music at will. But under the plan, record labels would license the songs to eliminate the copyright problems that have dogged Napster in the last year and a half.
Only Bertelsmann, which owns BMG Entertainment, has given the go-ahead for Napster to use its music, however. The other four major record labels have so far declined, saying they have yet to be convinced that Napster has a way to prevent future unauthorized copying of songs.
The file-swapping company has said it is working on a security component of the service, which will be provided partly by Bertelsmann subsidiary Digital World Services. The Los Angeles Times recently reported that Napster was also in talks with Microsoft for copy-protection technology.
Napster executives have said the new service is likely to cost between $5.95 and $9.95 a month depending on how much music consumers want to download. Songs downloaded would be limited in audio quality and unable to be burned to CD.
The free service will disappear shortly after the subscription service begins, executives have said.
Since Napster unveiled plans for its service, the big record labels have announced several rival subscription programs. Few details have emerged, though, about how those services will offer music to consumers, or in what format.