|The Stylus Phantasticus is the style of a free and unrestrained form that accounts for the method of composing and playing. This kind of music is truly passionate and involves improvisation. The term Stylus Phantasticus is used to designate free improvisatory music in the Baroque period in Germany. However, its presence gradually began as a reaction against polyphony in the toccata genre in the Renaissance period in Italy. The use of homophonic texture in the Venetian School and the dramatic dissonance of the Neapolitan School led to expressive toccatas in Frescobaldi`s music. The "fast homophonic toccata", used to represent certain groppo, recurring motives with flexible tempo made Stylus Phantasticus a reality. The sectionalization, texture, ornamentation, and church keys (tuono, tono) of Toccata are the decisive factors in the expression of Stylus Phantasticus. The Italian keyboard Toccatas of Frescobaldi represent Stylus Phantasticus in expression, and support contrasting texture, sectionalization, elements of virtuosity, ornamentations, church keys, and chromaticism. Girolamo Frescobaldi`s (1583-1643) from The First book of Toccatas and Partitas (Il primo libro di Toccata et Partite) and from Fiori Musicali are representative works composed in the Stylus Phantasticus. Frescobaldi indicated performance practice in his preface of The First book of Toccatas and Partitas that induced Stylus Phantasticus. The musically fantastic sound of his improvisatory style was induced by Toccata-Ricercare-Toccata sections in the and ``durezze e ligature Toccata``-``fast contrapuntal Toccata``-``slow homophonic elevation Toccata`` in of Fiori Musicali. The general character of toccata by Frescobaldi is rich, bold, often dissonant and chromatic since his toccatas were under the influence of church keys according to conventional Italy Toccata that adheres to old custom. The practice of ornamentations, church keys, sectionalization and tempo rubato of Frescobaldi leads to a forceful emphasis on madrigalism, leaving the organist free to improvise in Stylus Phantasticus. In conclusion, the toccatas of Frescobaldi are characterised by diversity in sectionalization, contrast in unique texture, repeatation in figured ornamentation, and transposition in church keys, and mark the successful culmination of the Stylus Phantasticus.