GERO, Jhan, commonly known as Maistre Jan, Jhan, or Jehan, and styled 'Joannes Gallus' in the title of one of his publications, was probably a native of France or Belgium. His earliest known work is a motet, 'Benignissime Domine Jesu,' in the 'Motetti della Corona' (Petrucci, Fossombrone 1519), so we may assume that he was born towards the close of the 15th century. He was chapel-master of the cathedral at Orvieto, and afterwards held a similar position at the court of Hercules II, Duke of Ferrara, and his successor Alfonso. Gero was a most voluminous composer of motets and madrigals. For the former, like Josquin and Lassus, he made choice of most important subjects, setting to music the ten commandments, the conversion of St. Paul, and parables from the New Testament. As a madrigal composer he was very successful, and enjoyed a lasting popularity. In a collection of madrigals for 3 voices printed by Gardane in 1597 (of which the bass part is in the British Museum) 20 numbers, more than a third of the whole, are by Gero. Eitner's 'Bibliographie der Musik-Sammelwerke' (Berlin, 1877) gives a list of more than 100 of Gero's motets and madrigals. Of these 32 appear in the 'Trium vocum cantiones centum' (Nuremburg, Petreius, 1541), 14 in the Second Book of Madrigals (Venice, Gardane, 1543), and 9 in the 'Madrigals for 3 Voices' (Venice, Gardane, 1561). The rest appear in smaller numbers in various collections printed between 1519 and 1590.