"Rick and John would exchange ideas and songs and they had a very common meeting ground."
Recording the new album was spread out over many months.
"It depended how he felt at that point," says Robin of Cash. "He didn't feel that well (when it started). He would do one or two tracks. Most of it was done essentially this spring."
Scruggs concurred about Cash's health in the process, but that changed.
"The one thing that was so inspiring to me was the sound of Johnny's voice throughout the recording," he says in an interview from New York. "He was continuing to get stronger. His health took a huge upturn. His voice had a real spirit and sound that there was no limit to it. So, it was real inspiring to me to see that happen."
Fortunately, Cash's health improved during last fall. "He was getting better in the fall," Robin says. "He did a few things when he felt good...If he wasn't happy with them in the final analysis, he redid them in the spring."
Robin says Cash "did a lot at his home. He finished at Rick's home. He put the finishing touches on what they had done earlier."
Overseeing the recording sessions at varying times were Rubin, Cash and his son, John Carter. "Sometimes Rick would come," says Robin. "Other times, John would do it with his son John Carter watching over the sessions. Then, they would send them over to Rick."
The Los Angeles sessions lasted a week.
While Cash has done few interviews for his album, his liner notes tell where he was coming from in recording "American III: Solitary Man."
"Recording in Tennessee isn't much different than recording in California; the song is the thing that matters," Cash writes. "Before I can record, I have to hear it, sing it, and know that I can make it feel like my own, or it won't work. I worked on these songs until it felt like they were my own. 'Mercy Seat,' 'Solitary Man,' 'I Won't Back Down.'"
Scruggs says, "He can be one of the true artists that has such expression in his voice. I just hear it and how he feels the lyrics when he's reciting or if he's singing. He does it with passion. It's something that is rare."
Scruggs, who never worked with Rubin before, was impressed.
"To me, it was always handled with great respect for the artisans. Very much a pleasure to work with him because I went into the attitude of respect of what he had done...If I'm comfortable in the particular studio environment I'm walking into, for me, it's easier setting to be creative and stay positive with what you're doing and your collaboration with the other musicians."
Cash writes, "When it comes to getting down and focusing on the songs and getting the job done, Rick Rubin does the job."
All the work on the recordings finished in the beginning of July. "They knew pretty much what they wanted, but they still had more songs than they wanted to put on the album," Robin says.
Cash recorded about 30 songs and knocked it down to 14.
"So, there's a lot of stuff in the can from previous sessions too," Robin says.
Robin says he did not get involved in the selection of songs. "That's just dialogue between the two of them," he says of the whittling down process.
"There's a lot of subjective judgment there."
Robin says it was his understanding that the selection depended on "just the motif of the album - the mood of the album that he wanted to set and that he and Rick agreed upon. And the songs were picked accordingly from material they had or someone brought to them."
"One" is a well known U2 song. Lead singer Bono and Cash previously met during Cash recording sessions.
Cash's version is far more subdued, less anthemic than U2. "It happened to be a song that he always liked," Robin says.
"Solitary Man" was written by Neil Diamond. "He likes that song anyway just like he did a Dean Martin song on the last album. He remembered the Dean Martin song from when he was younger," Robin says. "He saw an opportunity to maybe create some contrast on the (new) album - a song that everyone knew, let's say."
As for Petty's "I Won't Back Down," "John asked him to sing the duet for him on the album. John liked the song immediately." Petty and the Heartbreakers were the backing band on the "Unchained" album.
"The Mercy Seat" is a dark song from Nick Cave & The Bad Seeds. The song is about a prisoner facing the electric chair. "He seemed to know all about Nick Cave. It was something he wanted to do. It was something dark."
"I don't think it was meant to be a great hit," says Robin in an obvious understatement. "It certainly set the tone for the album."
Cash penned some new songs for the album and also culled songs he wrote many years ago.
"Field of Diamonds" was written with ex-son in law Jack W. Routh about 15 years ago.
"Laying on our backs and looking at the stars at our house in Jamaica, Jack Routh and I wrote 'Field Of Diamonds,'" Cash writes. "The unlikely duet of June and Sheryl Crow sang along with me, and it really felt comfortable. Sheryl came by on the last day of the sessions in Hollywood to sing with me and play accordion on a couple of songs."