With a new album, Carry Fire, out and a tour with the Sensational Space Shifters underway, Robert Plant is writing the latest chapter of a musical journey that began 50 years ago with Led Zeppelin. In a new interview, he discussed the secret of his musical longevity.

As he told the Toronto Sun, the key is to "stay in the groove of ceaseless creativity. When I sang the way I did when I was 17 or 18, when Bonzo, my buddy, played the way he did with me, we just did what we did. And that’s what I do now, and I think that’s the way forward."

But he also acknowledged that, as one broadens horizons, changes naturally occur within that person -- in the sounds to which he's exposed, in lyrical perspective and in the voice. And when that new outlook runs contrary to the past, Plant said that "means the way you play either has to be tempered according to that, or in my case, I couldn’t give a hoot. I just do what I do. That’s it. It’s a good time to be me because I haven’t dropped the ball at all. I just keep trying to open up the inside of, I suppose, a combined gift. Because the band and myself have sort of got this thing going on, which is really powerful."

Although Plant said he has no plans to retire, he doesn't begrudge his peers who are calling time on their careers. But he also understands the musician's temperament and knows that many of them won't be kept down for long.

"There’s no such thing as knowing when," he said. "Look, there’s so many different ways of expressing one’s self and doing what I really love to do. The thing about retirement is that you can retire for a month or a week or a day or you can just go to the movies and call that retirement and come up inspired. Send some of these people to some beautiful places where there is lovely music, and they’ll probably change their mind."