Buus composed (Catholic, Latin) motets, chansons (especially Protestant “chansons spirituelles”) and notably 18 elaborate ricercars for organ (the longest of which attains 358 measures), a free imitative genre — an instrumental counterpart of the Motet — which earlier became a tradition at Venice’s San Marco under Adriaan Willaert which was continued by the nephews Andrea Gabrieli and Giovani Gabrieli.
Jacob (or in French Jacques) Buus was a composer of the fourth generation of Flemish Polyphony, championed by Adriaan Willaert and Nicolas Gombert. He was born (probably) in Ghent. He may have begun his career in France and certainly maintained French connections throughout his life. In 1541 he became first organist of St. Mark’s, the duomo (cathedral) of wealthy Venice, which post he supposedly abandoned because of excessively low pay, becoming in 1550 or 1551 court organist in the Habsburg dynasty’s Imperial Chapel in Vienna, where he remained until his death.
[This contribution is mainly based on the HOASM-site, which links below, and KULeuven’s musicology professor Ignace Bossuyt’s book "De Vlaamse Polyfonie".]