by Stephen Thomas Erlewine 　　When it was recorded, nobody knew that MTV Unplugged would be 10,000 Maniacs' last album with Natalie Merchant. As it stands, it's a quiet, gentle way for her to bow out, offering no new revelations but several solid versions of the group's signature songs (mainly concentrating on Our Time in Eden) and a cover of Patti Smith's "Because the Night." It's nothing new, but for fans it's a graceful way to say goodbye.