Lulu, 67, was married to Bee Gee Maurice Gibb, is Rashida Jones' godmother, wrote one of Tina Turner's big hits (I Don't Wanna Fight) and was told by James Brown "you and I were born in the same pond".
The singer, songwriter and actor is enjoying a career renaissance thanks to last year's critically acclaimed record Making Life Rhyme.
The success of that record - and her appeal with a younger audience courtesy of her Take That duet Relight My Fire and her cover of We've Got Tonight with The Voice coach Ronan Keating - won her an invitation to perform at the Glastonbury Festival.
Gazing out at tens of thousands of young music fans cheering her on was "thrilling".
"I have been in this business a long time, I've been around and I've been down," she said. "It was mind-boggling to see the reaction because sometimes I feel like I am still waiting to be discovered."
• LuluLeo Sayer and Lulu play at Auckland's Civic Theatre on Sunday June 26 at 3pm and 7pm.