Including Grammy recipients, chart-topping singers, award-winning actors... and Jedward.
The Grease star became choked up as he paid tribute to his late friend and co-star.
"It has been my honour and continues to be my honour to be your baby and best friend."
"I always say to women, ‘If you have an instinct that something isn’t right, follow it up.’"
The former EastEnders actor said she was left "deeply moved" by the Grease star's death as she is now "starting my own battle" with cancer.
"What do you feel, what do you say when the nice, kindest and most loving woman leaves us to travel somewhere else."
"She was, and always will be, an inspiration to me in so many, many ways," Kylie wrote.
The pair played Danny and Sandy in the much-loved musical, and remained friends in the decades that followed.
The Grease star died on Monday morning "surrounded by family and friends".
Including Grammy-winners, chart-topping singers, award-winning actors... and Jedward.