In the early 1420s he was probably in the service of the Malatesta family in either Rimini or Pesaro, since Dufay mentioned him in the text of a rondeau which was written between 1420 and 1424.
Rome was entering a period of turmoil related to the Conciliar movement after the death, in February 1431, of Pope Martin V; many musicians left at that time or shortly after, and Lantins may have been one of them.
Lantin's music was held in high regard, and appears alongside that of Dufay, Gilles Binchois and Johannes Ciconia in contemporary manuscript collections.
Musically Arnold's mass movements are fairly simple, using three voices, head motif technique, and avoiding imitative writing.
He also wrote secular music, including ballades and rondeaux, all of which are in French, as well as a few shorter sacred pieces.