 In 1560, being a presbyter, he sought work as a chaplain and "altarista" by the church of "Santa Maria Annunziata" in Udine.In Udine, Mainerio spent ten years (from 1560 to 1570) and there, thanks to his previous musical knowledge and to the lessons given to him by two local contrapuntists, Gabriele Martinengo (Maestro di cappella from 1562 to 1567) and Ippolito Chiamaterò (Maestro di cappella from 1567 to 1570), he started his musical career.After three years in Udine he became interested in occultism (astrology, magic and necromancy) and there were rumours that—together with some women—he was attending night-rites.