Rod Stewart's voice is an octave lower since he was treated for thyroid cancer.
The 70-year-old received treatment on his thyroid gland in 2001 during a cancer scare and revealed while he was relieved he could still sing following the operation, it did result in him having a deeper voice.
Speaking about the health scare, he said: "It was benign but it was still a scary period. I couldn't sing for about three weeks - some people think that's a good thing. But the voice came back, albeit an octave lower, so I sing a little lower now than I used to."
However, his changing vocal ability hasn't affected his talent to entertain crowds, admitting they still "absolutely love it" when he sings his 1978 hit 'Da Ya Think I'm Sexy?' despite the fact it was criticised when it was first released.
He explained: "There was a period where I got tired of singing 'Da Ya Think I'm Sexy?' because it was critically slammed in 1979 and 1980 when it came out so I dropped it for a while. But I do it now and people absolutely love it because it sums up an era in their lives and an era in music - the disco era."
Meanwhile, Rod - whose new album 'Another Country' will be released on October 23 - said he is a fan of modern acts including Taylor Swift, who he commended for recently standing up against Apple's policy not to pay artists during a three-month trial period of their new streaming service.
He said: "I was knocked out with what Taylor Swift did you know about streaming, she spoke up and [was] very brave. She should sort out Fifa and the Greek situation, I think, she can sort out anything. She's brilliant."
Despite his fondness for the 'Bad Blood' hitmaker, he insisted he is "too old" to collaborate with her.
Speaking on ITV's 'Good Morning Britain' he added: "I don't think she'd want to sing with the likes of me, I'm far too old for her."
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