The City Chamber Orchestra performs an all-Vivaldi programme featuring the concertos composed for orphaned girls in 18th-century Venice. Benefits from Friday's concert will go to the Mother's Love charity for orphans in China. Thu and Fri, 8pm. St John's Cathedral, 35 Garden Rd, Central. Thu: $150, $250. Fri: $350, $650, including refreshments after the performance. HK Ticketing. Inquiries: 2857 2402