Sir Elton John has called Metallica's 'Nothing Else Matters' "one of the best songs ever written".

The 74-year-old star - who appears on Metallica's new covers album ‘The Metallica Blacklist’ - brought frontman James Hetfield to tears when he made a special appearance on 'The Howard Stern Show' to praise the track.

He said: "Listen, this is one of the best songs ever written. It’s a song that never gets old. And playing on this track, I just couldn’t wait. The chord structure, the melodies, the time changes, it’s got drama written all over it.

"I have to say, it was a no-brainer playing on this song. Metallica are probably the crème de la crème of those kind of bands. You can’t really define them. They’re not a heavy metal band. They’re a musical band. Their songs aren’t just heavy metal. They’re beautiful songs. This is such a melodic song — it’s f****** great, actually.”

Drummer, Lars Ulrich replied: "To be able to hear what you just said Elton, sitting next to James … the reaction that I could feel in his body language when you said it was one of the greatest songs ever written … this is just incredible to hear."