The Man in Black is back. Johnny Cash turns 70 on Tuesday, and the long-ailing singer says he's beginning to feel the itch to perform again. He's even finishing work on a new album.

"I've felt really good these last few months, better than I've felt in the last three years," he says.

Cash has diabetic neuropathy and is prone to pneumonia; since 1997, he has suffered frequent bouts, some that nearly killed him. He no longer tours, and he avoids the flu season in Tennessee by spending the winter at a second home in Jamaica.

Cash is planning a quiet birthday celebration Tuesday at home with friends, he said by telephone from Jamaica. He recently sang in public for the first time in years, performing "The Ballad of Annie Palmer" at a banquet in Jamaica for the Horatio Alger Awards Committee.

"It felt really good," Cash said, adding that he'd like to perform more "on some limited basis" if his health continues to improve.

"I think I hope and pray that all the pneumonia is behind me," Cash said. "It almost devastated me. Now I'm mending, and gaining strength every day and feeling good."

Sony Records is marking Cash's 70th by reissuing five of his albums (including Cash's favorite, Ride This Train) and the two-CD compilation The Essential Johnny Cash. Cash cut a duet with Dave Matthews for the soundtrack to the new movie We Were Soldiers. Two tribute albums are in the works and production on a film about his life may begin this year.

But Cash is most excited about his new album, American IV, his fourth collaboration with producer Rick Rubin. He has been steadily recording and hopes to have it released this year.

He has written at least one new song for the album, and will cover others by Sting ("I Hung My Head"), Roberta Flack ("The First Time Ever I Saw Your Face"), Paul Simon ("Bridge Over Troubled Water") and John Lennon (he's trying to decide between "Imagine" and the Beatles' "Norwegian Wood").

"I just look for the best songs that I can find, and record them in the simple, straightforward way that we do, you know?" he says. "Unadorned, very little production."

That style has served Cash well since he emerged in the 1950s on Sun Records out of Memphis. At first, he was the somewhat grim rockabilly alternative to wild cats like Elvis Presley and Jerry Lee Lewis. His first public performance was opening for Presley.

"That was at the Overton Park Shell in Memphis in 1955," Cash says. "I was an extra on an Elvis Presley show. I sang two songs."

Cash found his post-rockabilly footing in country music, becoming one of the biggest stars in Nashville with hits like "I Walk the Line," "Folsom Prison Blues" and "I Got Stripes." He has sold more than 50 million records, charted more than 130 hits, and branched out to film and television acting roles. He was inducted into the Country Music Hall of Fame in 1980, but has fans in other genres, too.

"He and Elvis were kind of in the same ballpark," says singer Glen Campbell, a fellow Arkansas native who first saw Cash perform in 1958. "He was very dynamic, but in a different way. If I could see anybody in their prime perform right now, I'd see Johnny Cash."

Ronnie Dunn of the country duo Brooks & Dunn said Cash has "that hip rock 'n' roll/country image that we're all shooting for. Even rock stars are chasing it."

In the liner notes to The Essential Johnny Cash, singer Bono of U2 calls Cash "the most male voice in Christendom."

"Not since John the Baptist has there been a voice like that crying in the wilderness," he writes. "Every man knows he is a sissy compared to Johnny Cash."

On his ABC variety show from 1969-71, Cash's guests included Bob Dylan, Neil Young and Joni Mitchell. The popularity of Cash's music dipped in the 1980s, but he found a new, younger audience in the past 10 years through his collaborations with Rubin.

Though his health has grown precarious, Cash has outlived many friends and contemporaries. The latest loss was Waylon Jennings.

"I've been richly blessed," Cash says. "I've just never fallen by the wayside. Elvis, Bill Black, Carl Perkins, you name it right on down the line, there's so many of them.

"Yeah, it is hard to see them go. But for every one that dies, I just thank God that he let me live."