Napster is appealing for beta testers to preview the company's new membership-based file-sharing service.

The new service is expected to launch this summer. The company and its partners (including one time courtroom rival BMG) will charge for this service. It will offer music for download that will be of limited quality. It will not be possible to burn tracks to CD.

The company is continuing its efforts to comply with the court injunction that requires it to filter copyrighted material from its servers. On its Web site, Napster says: "Some searches are not returning results, and many files are not being shared. Napster's filters are constantly being changed to more effectively exclude music the copyright holders want blocked, and that frequently results in other music being excluded as well."

The company assures its users that its engineers are working hard to develop new identification and filtering technologies. Appealing for loyalty, Napster says: "Your ongoing use of the service helps in the development and testing of these technologies. Thanks for supporting Napster."

Napster has placed a form-based email on the front page of its Web site for those interested in previewing its new service.