Keith Urban loves how Nicole Kidman doesn't try hard to be a "true artist".

The country singer and Australian actress tied the knot in 2006 and they have children Sunday Rose and Faith Margaret together. Since then Nicole has had an impact on Keith and his music, with him being in awe of how strong and determined she is.

"There's a fearlessness about Nic. It's funny, it's not a fearlessness, it's a willingness to face it anyway. That's a different thing. The characters she explores, she's really interested in and it's interesting because they've certainly, of late, been fascinating, strong, often misunderstood type characters," he explained to

"I love that she wants to bring them to life and present a new way to look at them. The reason I could never act is I'm terrified of looking stupid or failing in some way and it's something I'm really trying to work through. She doesn't have that sense of having to please people as much as just be a true artist. I love that about her. She doesn't mind failing at stuff to get to the place where it works... So I think she's helped me shed some of my limitations. That's very liberating creatively."

Keith released his record Love, Pain & The Whole Crazy Thing the same year he and Nicole tied the knot and the album contains his Grammy award-winning song Stupid Boy. Shortly after, the 46-year-old musician checked himself into the Betty Ford Center for drug and alcohol addiction. He remembers how his wife kept him strong throughout the difficult time.

"The first thing that I think about with this record is how everything's about to come undone, not long after this [album cover] picture was taken, actually. I'm already in a bit of trouble. We shot this over in England where Nic was doing something at the time. I think we were mixing [the album] to coincide with her being there," he recalled.

"I wasn't in any recovery program of any sort. I wasn't in AA. I didn't have a sponsor. I didn't have anything. Meeting Nic and falling in love with Nic and starting a relationship with Nic became - I realise now in hindsight - my sobriety. That was how I was able to keep it together."