Yep, that's it! I was using "through" in my search on iTunes, but when I used "thru" it came up with versions by Earl Scruggs and Randy Scruggs. (No Joan.)

Now I think it was the American Music Awards show, not CMA. I don't even know who the singer was -- a guy with dark hair. Didn't recognize him, but the song grabbed my attention.

Now I need the chords to save me from working it out myself!

Thanks!