"I know the Rolling Stones are in their mid-fifties and still rocking but I'm known for big rock anthems and I can't see myself carrying on singing the big screaming notes that only dogs can hear. I've never wanted to be a bloated parody, because what you see of me on stage is an extension of who I am. It's all me - just turned up louder.
"Now, I want to do something more intimate - more singing than screaming and turn the guitars and drums down a bit. Today I can still do it without compromise and I can guarantee it - but in a couple of years I don't know if I will be able to actually stand there and still be the Prince of Wails."
That's not the only change for the rocker who was unknown until he read in Melody Maker how Deep Purple wanted a singer. He has discovered there are more important things than music.
"I'd considered that music was my first love, the be-all and end-all. Then I got a call when I was recording with Jimmy Page in Miami, telling me that my mother, who I thought was in remission from cancer, had only three weeks to live.
"Suddenly I felt utterly empty. No thought beyond - it's impossible. It was dreadful - such an indescribable assault of emotions. Grief took on a whole new meaning and became the deepest well of emotional sorrow that I've ever known. Everybody was very caring - particularly Jimmy Page. He gave me his blessing. I made no apologies to anybody - I had to go.
"During the flight back to England, I had many hours to try to come to terms with this news and part of me was thinking `maybe we could do something about it. My money could pay for this.' When I was a boy, she had really sacrificed herself for me so when I joined Deep Purple the first thing I did was buy my mother a house - all the stuff a lad is supposed to do for his mam. I told her she would never have to work again but later I discovered that she was moonlighting as a barmaid!
"I found her at home in quite a lot of pain. The cancer and the chemotherapy had really aged her. I went through all these emotions: fury at medical science because I was being personally confronted by the fact that even by the end of the millennium they still hadn't produced a cure for cancer.
"We did better than two or three weeks - we managed almost three months. All I wanted was to give her little moments of joy. A very dear friend of mine has a beautiful restaurant and he would prepare some of his most delightful dishes for me to take home to her to have a nibble on. These moments of normality are particularly precious - because she had cared for me so deeply, it made the role reversal particularly poignant. I cried a lot.
"My daughter, Jessica, flew to join us - she was living with her mother in Zurich at the time. Such courage because at the time she was only 14 years old. I said, `I will fully understand if you don't come because it is a very sad time.' I understood because I was so close to my own grandmother that when she had died I couldn't go the funeral. I was too emotionally distraught. I think that was the first time I was confronted with death and I didn't have the balls. So my partner at the time represented me, which I now regret, but there was no way I could have dealt with it. I've grown since. At least I would like to think so.
"A lot of the time my mother didn't want me there - particularly as the cancer was kicking into the meanest part of the journey. I spent the last night with her. I spent my first day on this planet with her and so it seemed appropriate that I should spend her last day with her too. She didn't want me there for the actual demise. She loved me so much that even at that stage she was protecting me and didn't want me see her pass away. The nurses let me sit with her body and I thanked her for everything - not in a morose way but chatting about favourite times. I kissed her head and said my final goodbyes.
"My driver drove me away from the hospital and I turned to him and said: `Billy, I'm an orphan,' but he replied, `You're never an orphan when you've known the love of your parents.' It was such a magical thing to say - like having warm water poured over a cold heart. After the cremation, I went round to every place I'd lived because for some reason I felt the umbilical cord was cut.
"I've learnt to take nothing for granted after this loss. The positive was that I realise how fragile life is - I hold my loved ones and hug that much closer and value them above everything. My son has just passed his first birthday and had an ear infection; my heart bled. I want to give them the pure dedication I received from my mother and to make them as proud of me as she was of me. Music is still remarkably important to me but my family comes first. If they said, `David' or `Daddy, we don't want you do this anymore' - I wouldn't. Simple fact.
"Now that music isn't so important to me, I can enjoy myself more. What's more, I have a remarkably secure platform to launch from. My missus doesn't care that I'm called the last great rock star. Years ago, I found it hard to put on the husband and daddy jacket when I walked in the front door. I was still David Coverdale rock singer. Now whether it's age or personal happiness it's the easiest thing in the world to slip on those particular garments. I'm not living rock'n'roll 24 hours a day because I no longer have the ability to recover from all the parties. When I'm on stage I can still open the right door and let the beast lose! Yet I'm a pussycat when I'm playing on the floor with my son."
David Coverdale and Whitesnake play Manchester tomorrow, Southampton on Sunday and Plymouth on Monday. Their new album, `Restless Heart', is on EMI, CD EMD1104