Joannes was trained as a harpsichord maker by his father. This came to an abrupt end when his father died on 11 April 1757 after a period of illness. Joannes was then 14 years old. Two weeks earlier, on 23 February 1757, his father Johannes Daniël had arranged his inheritance. The ailing Daniël wanted his business in Antwerp to continue. He did not want to rely on his eldest son Johannes Lodewijk, who was now married to Catharina Koning and had set up a successful business in Amsterdam, and there were indications that Susanne was also in poor health. He therefore had an appendix added to his will stipulating that, after his death, Joannes would receive the tools and instruments needed to make harpsichords and organs. It also stipulated that Joannes had to support his youngest sister Joanna Elisabeth (born 3 February 1747). 

After his father's death, Joannes continues the business together with his mother Susanne and his brother-in-law Johannes Herman Faber, who is married to his eldest sister Joanna Henriëtta. They sell harpsichords not only in Antwerp but also in Brussels. Meanwhile, family relations remained good. When Johannes Lodewijk and Catharina's first child, Susanne Maria, was baptised in the Westerkerk in Amsterdam on 22 July 1757, grandmother Susanna was a witness. And when their fourth child, Jan Lodewijk, was baptised on 9 August 1761, Joannes himself and his sister Maria Sophia were witnesses.

Gedaan, 25 januari 1764

Meanwhile, business in Antwerp was going badly. There was a lot of competition. In April 1763, when Joannes was 21 years old, he and his mother decided to move to Brussels. The Magistrate of Brussels refused to grant them citizenship and the associated tax benefits. Despite this negative response, they decided to sell their house and business in Hopland. In Brussels, too, business did not go as expected and, in order to “prevent her from bread shortage”, they were granted an exemption by the States of Brabant to sell instruments in Antwerp, Leuven and surrounding areas. They took a large number of instruments with them from Antwerp. One harpsichord is known to have been sold in 1769 under the name Johannes Daniel. Unfortunately, the move to Brussels came to nothing. Somewhere between 1765 and 1769, it was decided to close the business. In 1771, Joannes was found in Amsterdam and his mother Susanna went to live with her son in Hasselt (Overijssel).

In 1772, Joannes moved to The Hague and on 15 November he registered his intention to marry Sara Brull, born in Gulpen near Maastricht. (The wedding took place on 29 November in Scheveningen). They went to live on Toornstraat near Haantjes the baker. There, in the ‘Gekroonde Land van Belofte’ several harpsichords made by him were raffled off.

In 1773, he moved to Westeynde near Slop van de Drie Boeren. There he presented himself as a master harpsichord maker and offered, among other things, a harpsichord made by Ruckers, which he had extended to five octaves.
On 21 May 1775, their daughter Suzanna Maria Sara was baptised in St.-Jacobskerk. On the same day, 21 May 1775, Johannes van Dulcken and Sara Brull drew up a will in which the husband is referred to as a “clavercingelmaker” (a maker of harpsichords). 

Two months later, Joannes became very ill. On 22 July 1775, he died at the age of 36. The cause of death was recorded as “cramps in the intestines”. A month later, on 21 August, their daughter Suzanne also died “of rotten fevers”.

Of his harpsichords made in Brussels, one from 1769 remains. A harpsichord from 1764 was destroyed in Berlin during the Second World War.

« IOHANNES # DANIEL # DÜLCKEN # ME # FECIT # BRÜXELLIS # ANNO # 1769 # »

Johannes Dulcken was 27 years old at the time, and his father had already been dead for 12 years.