There's a quality to Hank Williams' songs, a logic found deep in the harmonic structures which hold up the beautifully contoured melodies, that is still a model for songwriters in every field of popular music, not just country. It can be heard in all of his songs, but a good one to start with is "Jambalaya" (http://www.youtube.com/watch?v=xnKOVPXhlnE), in which an incredibly distinctive tune is supported by seemingly simple chords. But they aren't, of course; there's a great complexity to them, and not in a predictable way either. I've still never heard a cover version of this song that I find convincing.

"Cold, Cold Heart" (http://www.youtube.com/watch?v=cQmzp-NA5PM) is another exquisitely crafted song, but I can't say that I haven't heard it done well, because of this: http://www.youtube.com/watch?v=GERZo2wnaCY