This male was singing right in front of me and Josh Rose in a power-line right-of-way, but was very difficult to spot. Once we located him, he was pretty tame. He was clinging vertically to the stem of a forb, either head down or head up, and singing almost constantly, a throbbing "ZZZ ZZZ ZZZT." This was quite different than the continuous buzzy trill of the (presumed) Conocephalus all around.

In another photo (not shown), I got a partial view of the cerci, which is consitent with the illustration at Singing Insects of North America.