Most courts and municipalities had their own set of trombetti. Among their duties were playing in the grand processions, announcing royal proclamations, playing signals at public executions, and serving as messangers (Aragon, pg. 100). There are also accounts of them in (or near) battles. The general consensus on these trombetti is that they were not so musical or artistic as they were ceremonial and functional. They were very likely of a poorer background than many of the singers or wind players ( Lockwood), but earned a very decent salary. "Thus the leading trumpet-player at the court of Ferrara, one Raganello, earned 252 lira (=about 78 ducats) in 1503, more than any singer at the court except Josquin." ( Aragon, pg. 100).
Judging from their role and the natural limitations of their trumpets, it is unlikely that the trombetti had, or needed, any sort of notated music. They live on today, in some form, as the army bugler (as you know, a bugle is a valveless trumpet-like instrument).