This episode was ok. I was certainly kept wondering about the nature of the artifact. I just don't get how the song had the effect; I mean, yeah the acoustics thing makes sense; but when has ANY song done anything close to what that song did? Not many, although I do get choked up when listening to certain love songs (You belong with HER, damn it!) All in all, a pretty ok episode. I don't think it was the best of the series, but what the hey? It's the second episode.
On a completely unrelated note, the sixth Hitchhiker's Guide to the Galaxy book comes out October 12th. "And Another Thing..." by Eion Colfer.