Ah, there are several anime series which are of note due to strange phenomina. Gatekeepers had the piano-playing mecha, and Key had the robot singing songs which sucked people's souls out (okay, so it's not precisely right. Close enough for government work).

I liked Key and Gatekeepers up until the 'end'. No, they have no similarities at all to each other, not even on the surface, except that their 'endings' really weren't. I hear there's a Key movie I have to watch for the real ending, while Gatekeepers' 'ending' -was- the last episode, and extremely irritating due to insufficient character development (ooh, look, ten characters with actual emotions and pasts that we've spent all this time developing! Let's completely ignore them!)

-Craig
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