Besides collecting pictures of musical instruments and performances, Dr. J.W. Niemeijer amassed a reasonable amount of portraits of composers, musicians and more in general people related to music.
A striking one is the supposed-to-be portrait of Johannes Couchet (1610-1655)* Flemish harpsichord maker active in Antwerp within the school of the Ruckers family. The RKDexplore database has a full record of the painting, with literature as well. Among the pictures here below, also the painted lid of one of the instruments one of his heirs built in 1679.
According to Jan Kosten**, the portrait might have been painted by the painter Gonzales Coques (1614/18-1684) also active in Antwerp at about the same period Couchet was. In many of his paintings, Coques included harpsichords that were likely drawn after actual instruments, possibly by Ruckers or Couchet.
The portrait was included in the Amsterdam Sotheby’s catalogue of the 4th of November 2003, lot 92 and the description reads:
Flemish school, early 17th century; A portrait of a man, said to be Johannes Couchet, aged 45, half-length, leaning on the back of a chair. Dated, inscribed (?) with the name and age of the sitter upper left: A. 1643 / iOANNES COVCHET / obiit 12 Apriliis anno 1655 / A:tatis Anno 45 (?); oil on panel, branded with the maker’s mark of Guillam Gabron (active 1609-after 1662). 24.5 by 22.3 cm. The depicted man is identified through the inscription as Johannes Couchet (died 1655), who was the nephew of the famous Antwerp clavischord (sic!) builder Hans Ruckers and entered the guild of instrument builders in 1643. He worked together with his famous uncle, and was the restorer of the organ of the Antwerp cathedral.Sotheby’s (Amsterdam) 4th November 2003, lot. nr. 92
In his article, Kosten argues that Constantijn Huygens (1596-1687) ordered at least two instruments to the builder. Also, although the actual date of death of Couchet was the 4th of April and not not the 12th as reported in the inscription within the portrait, Kosten published a very interesting drawing with poem that Huygens himself drafted on April 8th 1655.
This Grafdicht, litterally Tomb poem reads:
In dese kromme kist rust Ian Couchet; met reden: / Sij beeldt syn ambacht uijt en past op syn’ leden / De korst na de Pasteij. Dan leser, weet daer bij, / Hy light niet op syn rugg, maer op syn’ slinckse zij / 8. Apr. 1655.
The poem refers to the peculiar shape of the coffin, which hints to the profession of Couchet and his family. More importantly, Huygens reports that inside that harpsicoffin the body was not lying on his back, but on the side, since the instrument builder suffered of humpback!
**Jan Kosten, ‘Het portret van de Antwerpse klavecimbelbouwer Johannes Couchet I (1610-1655)’, RKD-Bulletin, extra nummer, juli 2007, p. 15-20