Sydney Opera House: Concert hall opens after two-year makeover

The works were the largest and final part of a 10-year, $300m upgrade to the inside and outside of the world heritage listed opera house.

The multi-million-dollar concert hall project delivered extensive improvements to the venue, including: better acoustics for artists and audiences; enhanced accessibility; and new state-of-the-art theatre machinery and staging systems.

Above the stage 18 new acoustic reflectors have replaced the old clear acrylic 'donuts'. The 'acoustic petals' are set in a range of different positions, depending on the music being played. They are magenta to match the colour of the concert hall seats chosen by architect Peter Hall.

There is now a state-of-the-art sound system and automated stage risers. Acoustic diffusion panels have been added to the venue's timber box fronts to provide for a more balanced and true sound for non-amplified performances.

The stage has been lowered by 400 millimetres to improve sightlines and create more intimacy between artists and audiences.

As well as being home to the Sydney Symphony Orchestra, Australian Chamber Orchestra and Sydney Philharmonia Choirs, the opera house also stages a growing program of contemporary music and performance, talks, comedy, circus, cabaret and more

The SSO will mark its return to the concert hall on Wednesday, with Mahler's mighty Second Symphony and new chief conductor Simone Young. Performances will run until Sunday, July 24.

Posting on the SSO's social media page ahead of the concert hall's official opening, Ms Young said "I can't tell you how excited I am".

"Sydney's been waiting for this for more than 50 years," she said. "We now have a concert hall stage that is real acoustic world-class space."

The Australian Chamber Orchestra posted "who can't wait to be back in those magenta seats?". "We personally can't wait to be back in the space for the first time on Sunday, August 14 for The Crowd And I."