Francesco Usper (* November 1, 1561 in Rovigno; † in February or March 1641 in Venice; birth name Francesco Spongia / Sponga) was an Italian composer, organist and priest.
Francesco Usper, descended from an Istrian noble family. He was a pupil of the eminent Andrea Gabrieli in Venice from 1564. In 1595 he dedicated his first printed works, "Ricercari, et arie francesi..." to the Venetian patrician Ludovico Usper, whose name he henceforth bore. The following year he became organist at the "Scuola Grande di San Giovanni Evangelista". He collaborated at times with Claudio Monteverdi and Giovanni Battista Grillo. He was appointed tas he first organist at St. Mark's Basilica in 1623. Usper is considered the first composer to have used the technique of the concerto grosso in the first sinfonia of his "Compositioni Armonice" in 1619. This prompted the music historian Alfred Einstein to state "A concerto grosso from 1619." In the ecclesiastical hierarchy, he was elected "Capo di Chiesa," the head of the priesthood at the Scuolo Grande di S. Giovanni Evangelista in 1624.
His nephew Gabriele Sponga was also a composer. One of his works (Trio Sonata) has some importance in early violin music.
Wikipedia

Note: Translated from the Geman version of Wikipedia into English.