rhythmic soothing nighttime sound of katydids, maybe

After comparing the sounds on my video to the sounds on the katydid video that I originally thought it sounded like, they no longer sound the same to me. And when I search on katydid sounds, the results come back with all kinds of different sounds. So now I'm not sure if the ones in my video are really katydids, or if they are something different. Can anyone confirm/deny?

"Are these Katydids? Nighttime tree critters, rhythmic sound" (Watch on YouTube)

https://www.youtube.com/watch?v=ygKxG3MG3DU

The first 10 seconds of the video is the kind of sound that I find most relaxing/hypnotic... it's like 2 critters take turns calling, back and forth, back and forth, each with a slightly different pitch, higher, lower, higher, lower...