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]}