The mass participation, multi-location event will involve thousands of musicians around the world.

To mark this year’s Earth Hour, the annual ecological awareness initiative, the Sydney Symphony Orchestra will lead the inaugural Concert for the Planet. For the event, the Sydney Opera House will become the still point of the turning world as the SSO, under the baton of David Robertson, lead the Global Orchestra in a performance of Holst’s The Planets on the evening of March 28, which will involve musicians all over the world.

The “mass participation, multi-location” event, which the Global Orchestra claims is the first of its kind, will see musicians from across Australia and the globe, including hundreds of school groups and community orchestras, simultaneously performing Holst’s famous, cosmologically inspired orchestral suite. Thousands of musicians are expected to join the Global Orchestra performance, performing along with the SSO remotely via a live stream from the Sydney Opera House using a special “conductor-cam” to capture David Robertson’s directions from the podium. The live broadcast will also include helpful cues and bar numbers to assist in coordinating the multinational ensemble.

One of the ensembles registered to take part the performance of The Planets has aptly out-of-this-world credentials: 70...