In Leiden, Pieter played the organ regularly in the Mare church, named for its location on Mare Street, a central arterial in downtown, and formerly a canal which had been paved over. Like the St Nicholas church in Utrech, it was well known as one of the first Protestant churches in Netherlands. Pieter did find a stream of paid gigs, playing for and with music enthusiasts and amateurs around the University of Leiden. For two years, 1749 until 1751, he continued his musical studies at that University.