"She would ask me my opinion, and I'd always say, 'The best advice I can give you is go ask Narvel (Blackstock.)' So she did," McEntire told USA Today.
Clarkson said McEntire was an early influence on her musical style.
"She has that big, soulful, kind of sassy voice but can also pull off a beautiful ballad," Clarkson told the newspaper. "It's good for every young singer to have somebody they can model their careers after."
The two singers are collaborating professionally, having already produced a hit version of "Because of You" from McEntire's new "Reba Duets" album.
"It's an odd but warm relationship," observed Chet Flippo, editorial director at CMT.com. "Kelly is Reba's musical daughter. They're completely without artifice together."
The two first sang together in 2002 on an "Idol" special, but the friendship really sparked during a February taping of "CMT Crossroads."
They had already done one song together for the album but McEntire said when Blackstock heard them rehearsing "Because of You," he said: "'OK, we've got to do that one.' So we went back in the studio."