Johnny Cash speaks from the grave on last 'American Recordings' album

LOS ANGELES -- Johnny Cash's voice comes in with a rumble, singing that there "ain't no grave that can hold my body down." A shuffling beat that sounds like heavy chains being carried back and forth accompanies him.

It sounds both reassuring and, let's be honest, a little creepy.

He's been dead for six years now. Even a voice that iconic can't speak from the great beyond, can it?

No, it's what he left behind -- the sixth and last of the American Recordings series he made with producer Rick Rubin. The disc, "American VI: Ain't No Grave," will be released today, which would have been Cash's 78th birthday.

Like the series' fifth disc, also released posthumously in 2006, it contains mostly recordings made by Cash in the last few months of his life. His way of working through the grief over his wife June's death, also in 2003, was to work as much as his health permitted.

"When we first went back and listened to the recordings after he had passed, it really just felt like this voice coming back from another place," Rubin said. "It had all this weight and gravity to it. It was scary."

You can hear the good days and bad days in his voice. Sometimes it's weak, as if Cash was struggling for his breath. Other times it's stronger, more familiar to fans who have listened to him for decades.

When he had finished the fourth disc of the series that gave him a professional rebirth, Cash thought the run was over. He was a little melancholic -- until Rubin told him they should start the next one tomorrow.

"His eyes lit up," he said. "He really got excited. He didn't know if he could do it, he didn't know if anybody cared that he could do it. He felt like he'd given what he had to give. The possibility that there was more for him to give really excited him and from that moment on, he was really on."

The recording style for this final disc was the same as it was for the other American Recordings. An engineer would capture Cash's vocal, perhaps to a single guitar accompaniment, and Rubin later brought in session pros like Mike Campbell, Benmont Tench and Jonny Polonsky to build an arrangement around it. The unadorned series of recordings were a late-in-life artistic revival for Cash, as he worked on songs expected and unexpected -- like the memorable cover of the Nine Inch Nails song "Hurt."

Along with the title cut, "Ain't No Grave," the songs Cash sings include ones by Kris Kristofferson, Sheryl Crow, Tom Paxton and an original he wrote in his last three years.

The final sessions produced enough material for two discs, and it was left to Rubin to decide how they would be configured. The 2006 disc was largely a rumination on mortality, but he feels the new one is more about how a person's energy can live on after death. The cover is a picture of Cash as a child.

"It does bring him back to life," he said. "He can live on by us being able to hear this, even though he can't show up and sing it for us. He left it for us to be able to feel him as if he were here."

Rubin usually selected songs for Cash to try, but the singer chose the traditional Hawaiian tune "Aloha Oe" and always intended it to be the final song of his final album. He enjoyed spending time in Hawaii and loved that song, Rubin said.

Cash's final words before the music ends: "Until we meet again."

"I loved him, and it was always inspiring to be around him," Rubin said. "I feel almost like a curator now, and I have to make sure that the usage of this music is with the highest intent, defending his work for the quality that I believe it has and make sure that it never gets used for the wrong reason."