pat

For good breakup songs, Travis Tritt's "Here's A Quarter (Call Someone Who Cares)" might be a good one.

I second the recommendation of k.d. lang and Alison Krauss. You might also try "The Bug" by Mary Chapin Carpenter. If he decides that instrumentals can work for him, get him the Charlie Daniels Band doing "Orange Blossom Special" -- I have a fond memory of finding a TV show closing with that song on a ferry to the Orkney Islands; what a nice breath of home. :)

I'll just start tossing out some ideas, with no consistent theme besides "I like 'em, and consider them at least vaguely country".

Alabama, "Mountain Music"
Hank Williams, Jr., "Family Tradition"
Indigo Girls, "Watershed"
Indigo Girls, "Southland In The Springtime"
Indigo Girls, "Get Out The Map"

(iTunes tells me that the Indigo Girls did a cover of "Mrs. Robinson" on the "Desperate Housewives" soundtrack, which also has Liz Phair covering "Mother's Little Helper". Alas, they're only available on the album.)

Soggy Bottom Boys, "Man of Constant Sorrow"
Chris LeDoux, "Little Long Haired Outlaw"
Chris LeDoux and Garth Brooks, "Whatcha Gonna Do With A Cowboy?"
Clint Black, "No Time To Kill"
Clint Black, "Galaxy Song" (yes, that's the Monty Python song, and it's just as funny as you'd expect)
Eagles, "Seven Bridges Road"
Eagles, "Desperado"
Dixie Chicks, "Goodbye Earl"
Dixie Chicks, "Landslide"
Alan Jackson & Jimmy Buffett, "It's Five O'Clock Somewhere"
Jimmy Buffett, "Margaritaville"
Charlie Daniels, "Devil Went Down To Georgia"
Charlie Daniels, "Legend of Wooley Swamp"
Charlie Daniels, "Uneasy Rider"
Lynyrd Skynyrd, "Tuesday's Gone" (I know iTunes calls it rock -- they're on crack. It's country.)
Patsy Cline, "Walking After Midnight"
Patsy Cline, "Crazy"
Patsy Cline... oh, hell, just get him anything by Patsy, it's all good.
Waylon and Willie, "Mommas, Don't Let Your Babies Grow Up To Be Cowboys"
Willie Nelson, "Blue Eyes Cryin' In The Rain"
Willie Nelson, "My Heroes Have Always Been Cowboys"
George Strait, "All My Exes Live In Texas"
Ray Charles, "Georgia On My Mind"

I'm sure I'll think of others eventually. I notice that very little of this is recent when I look at it, and I'm OK with that. I'm not conversant with the alt.country scene, but I've been very taken with much of what I've heard from it, and I'll bow to the recommendations of others.