This page http://www.lawrence.edu/fac/koopmajo/standard.html defines a trillo as "The multiple rearticulation of a single note with ever increasing rapidity. Later called martellato."
daniel • Link
Trillo is an italian term for a vocal, sometimes instrumental ornament used in music during much of the seventeenth century. this ornament's execution seems to vary in time and from place to place but mainly consists of a rapid, sometimes accelarating series of glottal stops on the same pitch used mainly at cadences. this ornament was criticized in later times as sounding a bit like a goat.
Chart showing the number of references in each month of the diary’s entries.