Listening to a Continent Sing

I've been stumped by a brief song like this before, back in a small bush in a sea of sagebrush in central Idaho. The hillside here is much the same, arid, just a few trees. And he's a mere ten yards from me, but it's still dark and I can't see him. Has to be an incomplete song of a lazuli bunting, perhaps one shortened during an energetic dawn chorus, and if I were to wait here for daylight, almost certainly he's show himself and deliver a more typical song. Maybe.

Background

American robin, house wren, another lazuli bunting, brown-headed cowbird (e.g., 0:50)

Photo by Robert Royse