That performance by Rebekah del Rio struck me enormously on a visual level as much as auditory. Red curtains, black-and-white zig-zag dress (remind you of somewhere?). The performance seems to go on far longer than any previous one, with lingering shots on Rebekah's dress backed by the curtains. Not to mention she's the singer in Mulholland Dr., and achieves much the same affect here.

The rest of the episode made me feel like something major was going to happen in part 11, but this sealed it for me: the next part will be significant. I don't know how, but it's just a strong feeling.