Provided that the context is almost certainly ecclesiastical, since the document is about an "Apostolic Visitation", a mixture has here been common between Italian and Latin, mainly because the official language was opposed to the vernacular, which can be regarded as an ancient form of Italian.
As Riccardo de Contardi commented in a previous answer, the title is in Latin and its meaning is (following Riccardo hints)
[He/it] is required to serve the choir of the parish church [inside the walls]
where "choro" can be probably intepreted as a vocal choir.
The second part of the text is instead Italian, without apparent Maltese influences:
Talking about choir service I won't get involved in it, nor it is my duty, since I am nothing but a simply parishioner, and in this place you don't serve the choir.
I try an interpretation: during the Apostolic Visitation the superior questioned about the choir service, arguing that the man whose words are quoted should do it; the man then appelled to the local laws (maybe just habits), by which he had not to get involved in it.