The 18-year-old Shostakovich, photographed June 28, 1925, two days before he completed his Symphony No. 1. Courtesy of Naxos Records hide caption

itoggle caption Courtesy of Naxos Records

Projections on the giant sails of the Sydney Opera House, which served as the venue for the YouTube Symphony Orchestra concert. Chris Phillips/YouTube hide caption

itoggle caption Chris Phillips/YouTube