The FTCO provides free public access to a thematic catalogue and database of all the known works of Girolamo Frescobaldi (1583-1643), including works of uncertain or mistaken attribution, along with all their early sources (up to approximately 1800), principal modern editions, and associated literature. It is a work-in-progress and may remain so for some time to come. We hope that with ongoing contributions and comments from the international musical and scholarly community, we will continue to improve the comprehensiveness, accuracy, and usefulness of the database.