Christmas is a time for beautiful harmony, and there are few bands in country music who deliver more perfect harmony than Diamond Rio. The band's latest single, 'Have Yourself a Merry Little Christmas,' is taken from the multi-award-winning group's 'A Diamond Rio Christmas: The Star Still Shines,' available at their official website. (Listen to the song below by clicking on the blue arrow.)

"It does my heart good to know the whole world is focused on the birth of the Savior," says Diamond Rio front man Marty Roe. "Such a message of unconditional love."

The group, consisting of lead singer Marty Roe, guitarist Jimmy Olander, drummer Brian Prout, keyboardist Dan Truman, bassist and harmony vocalist Dana Williams and mandolin player/harmony singer Gene Johnson, has been going strong since forming in 1984. Earlier this year they released their 11th album, 'The Reason,' on Word Records.

And speaking of going strong, the group is also in the middle of recruiting folks to join Team Rio for Nashville's Country Music Marathon and Half Marathon on April 24, 2010. It's the team's sixth year to participate. To date, 133,000 training miles have been walked and over $425,000 has been raised by the usual 230 total participants.

But while that event is still a few months away, and since the holidays are a time to enjoy family, friends and plenty of good food, Diamond Rio's Marty Roe wants to share this exclusive recipe for what he calls the "Devilish Love Bar." Sounds heavenly ...

Marty Roe's 'Devilish Love Bar' recipe

1 c. water

2 sticks margarine

1/2 c. cocoa

2 c. flour

2 c. sugar

1 tsp. baking soda

2 tsp. vanilla

2 eggs, beaten

1/2 c. buttermilk

Bring water, margarine and cocoa to a boil. Pour hot mixture into remaining ingredients. Bake in greased and floured 12X15-inch sheet pan. Bake at 350 degrees until set, about 20 minutes. Pour fudge icing over hot cake and sprinkle chopped nuts on top. Cut into bars when cool.

Fudge Icing recipe:

1/2 c, buttermilk

1 stick margarine

1/2 c. cocoa

1 box of confectioner's sugar

Nuts, finely chopped

Bring buttermilk and margarine to a boil. Add the remaining ingredients and blend with a mixer.