The Fiori Musicali of Girolamo Frescobaldi (1635) contains an anthology of organ compositions for liturgical use. With the Council of Trent, the presence of the organ within liturgy had become obligatory: in particular, the practice of the alternatim for the parts of the Ordinary Mass - brief organ interventions (versets) alternating with Gregorian chant - and the use of free pieces to replace some parts of the Proper (in the place of the Introito, after the Epistola, at the Offertorio, for the Communio). The Fiori represents an ‘exemplary’ collection. The dedication to Pope Urban VIII appears to be much more than required homage: it is symptomatic of the support of the liturgical policy promoted by the Pope. The main aim of the Frescobaldi collection is in fact to supply a high model of style and form for the organ repertory used in liturgy. The success achieved was rapid and lasting: both in Italy and in France, it represents one of the most used didactic repertoires, still in use, in our time.
