In the Beatles song (I hadn't heard it before), the voice fades out to a whisper (like you said, a lullaby), while the music has a definite last string chord...

That idea of the voice fading out ties (in my head!0 into the idea that as you drop from hynagogic into slow wave there's a point where the external inputs are shut off, an actual moment, but the conscious mind doesn't notice because its faded out from external inputs as the internal stimuli come louder.

And I've ordered the film to watch--I really enjoyed the images, the film got a panning from a critic and high praise from two viewers, so we'll see!

Don't fight forces, use them R. Buckminster Fuller.