The world’s first online collaborative orchestra is back, and this time a new round of performers will be playing their part onstage at the iconic Sydney Opera House.

It seems like just yesterday that Carnegie Hall was abuzz with a sold-out performance that made headlines around the globe. Ninety-six musicians arrived in New York City, from over 30 countries, to perform together after uploading an audition video and then being chosen by the YouTube community to be a part of the exciting event. We are thrilled to invite you to audition for the YouTube Symphony Orchestra 2011.

In addition to the new locale, this “second act” includes another new element: “Mothership,” a musical work from composer Mason Bates. Right now, it’s still missing something: an improvisation provided by you. Take a listen to it here and start planning your contribution.

This time there are two ways to audition, for the classical audition perform the pieces listed on the channel according to instrument. For the opportunity to contribute your own creation, choose the solo improviser—it doesn’t matter if you play trumpet, viola or didgeridoo. If you proceed to the final stages, you will join musicians from around the world in a week-long music summit with Grammy-award-winning conductor Michael Tilson Thomas, who returns to guide the orchestra.

The YouTube Symphony Orchestra 2011 is a collaboration with partners the Sydney Symphony, the London Symphony Orchestra, Berliner Philharmoniker and many other leading institutions of the classical music world. This event is being made possible by Hyundai.

Michele Flannery, Music Manager, recently watched “Eucalyptus Didgeridoo Solo