There is a long and detailed historical sketch of the burning of Schenectady at this website, with the ballad appearing near the end.
(click here)

Pp. 244-270 of "A History of the Schenectady Patent in the Dutch and English Times."
This comment is made: "The following ballad, though without much literary merit, has some value for the facts set forth therein. It was evidently writter by a person belonging to the English garrison stationed in Albany."

The version posted by cetmst corrects some of the mis-spellings in the 'original,' as given in "A History..."