French composer, possibly from the diocese of Sens. He was a chaplain at St Merry in Paris in 1418, and a matins clerk at Notre Dame in 1421. His Missa trompette (settings of the Kyrie, Gloria, Credo and part of the Sanctus) has passages of contratenor marked 'trompette', probably intended for the slide trumpet; his chansons have a delicate expressiveness. Compositions by Grossin, together with those of Zacharia, Ciconia and Egardus, appeared in Polish manuscripts in the early 15th Century. Also respresented in the Trent MS.