Operissimo is an online database based in Zürich,[1] which is dedicated to recording details of classical music concerts and opera performances. The database currently includes biographies on over 7,500 composers and 44,000 performing artists,[2] encompassing both historical and contemporary figures.[3] The biographies contain articles, without attribution, based on the third edition of the Großes Sängerlexikon. It also includes details on more than 47,000 performances,[2] 340 opera houses, and more than 55,000 recordings.[4][citation needed]