Jacques-Denis married 10 November 1653[3] with Hélène Dumelin, daughter of a Parisian goldsmith, who brought him 2400 lt dowry.
[4] On 8 November 1684, Thomelin, as the executor of Pierre Méliton's[5] will, organist of St. Jean Church, signed the inventory after the death of his deceased colleague (and probably friend).
His post-death inventory is known:[8] In addition to 3000 lt in cash, he left musical manuscripts that were donated to his widow (the latter moved to rue des Prouvaires with her eldest daughter).
The elder, Marie-Madeleine, born before 1660, married François Collesson, businessman and clerk of Dupille, Receiver General for Finance of Lyon, by contract dated 18 March 1695.
[16] In 1678, he became sufficiently well known to compete in the Chapelle Royale organist competition, organized to replace Joseph Chabanceau de La Barre who died, during which time this office was divided into four quarters.
[21] At Saint-Jacques-la-Boucherie like the Carmes de la Place Maubert, it was his nephew Louis-Jacques Thomelin (son of Guillaume) whom Jacques-Denis designated to replace him, at the charge of financing some minor repairs for the organ of Saint-Jacques, for defects that Jacques-Denis should have - according to the chapter - repaired in his time.