Gibb, Mike. Operabase http://operabase.com/en/

What more would opera singers need? This site contains a database with details of over 27,000 opera performances since autumn 2002 by any combination of opera title, composer, date, location; information about specified artists, their schedules, performance details, reviews, bios, discographies, etc.; opera city guides, information about opera houses, festivals, magazines, and more.