This is the only time that I have seen the word "passacaglio" in Italian as masculine and not feminine; it is usually "passacaglia." It is part of Biagio Marini's (1594-1663) last published collection of music, which loosely translates to "for all kinds of musical instruments, diverse genres of sonatas, for church and for chamber." in layman's terms a "catch-all" of what he had written. This particular pieces is probably for two violins, viola, and 'cello/bass but fits with absolutely no alterations on two soprano and one alto recorder. The bass line needs the occasional low D taken up an octave to work on bass recorder, but that is the sum total of editing needed. It is not an entirely typical passacaglia as it has more than one ground bass rather than repeating the same pattern the whole time. There is also a brief introduction and codetta in four (the body, as usual for a passacaglia, is in three) in case the counting feels off for some reason.