Robert Plant's music lets him "cry" about his late son.

Robert Plant

Robert Plant

The former Led Zeppelin rocker's five-year-old boy, Karac, passed away from a stomach virus in 1977 while was on tour in the US and though the 70-year-old musician has channelled his grief into his songs, he admits he'll never get over losing the youngster, who he had with first wife Maureen Wilson.

He said: "I've written four songs about my boy who passed away. It lets me cry. You know, with pain like that, it's never gone."

The 'Whole Lotta Love' hitmaker also suggested he gave up taking drugs after the death of his son.

Asked what he puts his survival down to, he told Event magazine: "I don't put it down to anything.

"There's a myth that surrounds artists and writers who don't spend their time refuting, denying things. I don't care whether I did or didn't do too much stuff.

"Some of the greatest work that's ever been created, the greatest projection and delivery of music, has come from stoners, but I had nothing to do with all that s**t, not since I lost my boy."

Despite his advancing years, Robert has no plans to retire until he stops finding playing music "magnificent".

He said: "Jimmy [Page] did an interview for the NME in the early Nineties, and the title was Help The Aged.

"But people don't clock off at 65 if they're doing what they love to do.

"Maybe in the end. None of it's worth a dime, but you can have a great time in the middle of it all. If you don't think it's magnificent to do this, then you really need to change the cassette and get off the bus quick."

Meanwhile, the veteran rocker insists he doesn't regret any of his lewd lyrics.

He insisted: "No, they're fine. I was just 20, I was a guy being driven by the excitement of the moment. Anyway, it's not as saucy as Prince."