Punk legend Iggy Pop has turned 70 with news he is singing on an experimental jazz album, saying the genre's bare exposure of his voice appealed to him artistically.
The "Lust for Life" singer, who turned 70 on April 21, contributes in three songs on New York pianist and composer Jamie Saft's upcoming "Loneliness Road."
Pop said that his voice on the songs has imperfections but that he decided they were appropriate.
"I was a little surprised at how feeble I sounded on certain parts of it, but I thought that was OK," he told Rolling Stone magazine.
Pop said he was drawn to jazz as "there's no big, bashing thing or echo trick to hide behind."
Saft, who has worked with artists as diverse as leading contemporary composer John Adams and hardcore punks Bad Brains, said he improvised around Pop rather than just having the star singer offer his voice.
"It's a deeper concept of original improvised music that transcends genre," he explained.
Pop, known for his intense live performances in which he works his bare-chested body into a sweat, last year released "Post Pop Depression" which had the air of a career-capping album.
His two previous albums had strong jazz influences -- "Preliminaires," which took inspiration from provocative French novelist Michel Houellebecq's "The Possibility of an Island," and "Apres," which is mostly covers of French songs.
Pop told Rolling Stone he was also working on music for an upcoming French film.
The rocker was able to reach 70 unlike his close friend and collaborator David Bowie, who died last year at 69 after releasing his jazz-infused final album "Blackstar."
Metallica frontman James Hetfield, 53, celebrated Pop's birthday over the weekend by releasing a video in which he pulls off his own shirt to show his heavily tattooed torso.
"You don't look a day over 30," Hetfield said of Pop, calling him a "huge inspiration" for musicians who are getting older.