: a leader of the singing of a choir or congregation
According to the New Advent Catholic Encyclopedia, in ancient Catholic history the PRECENTOR did a lot more than lead the choir. Other responsibilities included: intoned antiphons, psalms, hymns, and responsories on Sundays and feast days; gave the pitch to the bishop at mass; recruited and taught the choir; interpreted rubrics; composed hymns, sequences, and lessons of saints; oversaw acolytes, exorcists, lectors, and psalmists; and held a place near to the bishop in dignity.
That's quite a resume.
When I search the internet for the responsibilities of the modern PRECENTOR, I keep landing on a quote from the Bishop of Dijon: