Hello
It would not be possible to create a membership site with muse itself. We need a database where members data has to be stored. And muse does not include a database.
So you need a hosting service which provides you a database and then you can implement membership feature on your muse site.
If you host your site on Business catalyst, you can use the feature of secure zones and it can be implemented.
Please refer to this article : http://kb.worldsecuresystems.com/kb/add-secure-area-your-site.html
Regards,
Prateek