innovations of Petrus de Cruce, described a system of division of the breve into 2, 3, 4, 6,8, 9, or 12 semibreves (later minims) with dots (singular punctus divisionis) indicating breaks at the end of a breve (however, Marchetto never used a term "punctus divisionis"). Although more Trecento music is written in the international system of notation descended from Franco of Cologne and Philippe de Vitry than in the Marchettian system (and there exist a few, mostly instrumental, works not of Italian origin that use this system), nonetheless, Marchetto's contribution to rhythmic notation is so connected with the Italian Trecento that it is often referred to as simply, "Italian Notation." Birth of the Trecento style (1330–1360) Much of the earliest polyphonic secular vocal music of the Trecento to survive is found in the Rossi Codex and includes music by the first generation of composers to craft a uniquely Italian style. Though many works of this generation are anonymous, many works are attributed to one Maestro Piero and Giovanni da Cascia. Other composers of the first generation include Vincenzo da Rimini and Jacopo da Bologna, though they may be of the later end of this generation. All of these composers were associated with aristocratic courts in the north of Italy, especially Milan and Verona. Some extremely obscure names survive in later sources, such as Bartolo da Firenze (fl. 1330–1360), who may have been the first Italian composer to write a polyphonic mass movement in Trecento style: a setting of the Credo. The two most common forms of early Trecento secular music were the two-voice madrigal and monophonic ballata. Some three-voice madrigals survive from the earlier periods, but the form most associated with three-voice writing was the rarer caccia, a canonic form with onomatopoeic exclamations and texts that make reference to hunting or feasting. While some of their music was still monophonic in the manner of the preceding century, much was for two voices, and Jacopo da Bologna wrote a few madrigals for three voices. Jacopo wrote one motet which has survived. Florentine music in the mid-to-late fourteenth century (1350–1390) The center of musical activity moved south in mid-century, to Florence, which was the cultural center of the early Renaissance. Characteristic of the next generation of composers, most of them Florentine, was a preference for the ballata, a form which seems to have exploded into popularity around mid-century. Like the closely related