Delta Goodrem shocked her fans on Monday night by bringing out a very surprising guest to perform alongside her at the Sydney Opera House.

The veteran singer, who was performing a special concert in celebration of the 20-year anniversary of her Mistaken Identity album, was joined onstage by Cody Simpson.

Delta, 40, and Cody, 27, looked at ease as they performed an emotional duet of her song Almost Here, which she originally sung with her former boyfriend Brian McFadden.

Cody later took to social media to reflect on his career milestone. 

‘Thank you to the legendary Delta Goodrem for the honour tonight,’ he began. 

‘It was a pleasure to sing at the Sydney Opera House for the first time, and to celebrate the 20th anniversary of Delta’s album Mistaken Identity.’

The special performance was held to celebrate the immense success of Delta’s second album, which reached number one in Australia and also charted in the UK and New Zealand. 

Earlier this year, Delta revealed the advice she would give herself at the start of her career. 

The singer said she is currently in her ‘best era’ and wishes she’d enjoyed her career more. 

‘If I could go back in time, and speak to my younger self, I would say, “It gets more fun”,’ she tells the Herald Sun. 

‘As time goes on, you really enjoy it because you know the craft. You move forward.’ 

Delta, who is releasing her new album ATLED, says she is the happiest she has been as a person and musician.

‘I’m the best version of an artist that I’ve ever been,’ she said.

It comes after Delta shared the poignant story behind a photograph of herself that has remained unseen for two decades.

Taken in 2004, the image shows the then-19-year-old star in London, promoting her second studio album, Mistaken Identity – a record deeply intertwined with her personal battle with cancer.

While the Australian singer-songwriter was set to embark on an exciting new chapter in her career at the time, her life took an unexpected turn when she was diagnosed with Hodgkin lymphoma.

Hodgkin lymphoma is a type of cancer that affects the lymphatic system. Some of its common symptoms include swelling of lymph nodes in the neck, armpits or groin, fever, tiredness, night sweats, weight loss and tiredness. 

The devastating news meant that her plans to perform and promote the album on a global stage had to be put on hold as she focused on her health.

Fast forward 20 years, Delta is now gearing up for a triumphant return to the spotlight, with a long-awaited tour to celebrate her journey and music.

The tour will kick off with an intimate performance at the Sydney Opera House on April 14, 2025, with an additional show announced for April 15 due to overwhelming demand.