- Profession: Professor of theology, partner at distillery Lever & Co.
- Relation to Mahler: One to the initiators and founders of the Amsterdam Royal Concertgebouw, who knew each other from the Old Exchange (Oude Beurs) in amsterdam, where they formed a "musical" group.
- Correspondence with Mahler:
- Born: 12-09-1837 Amsterdam
- Died: 06-01-1895 Heemstede. Aged 57.
- Buried: 00-00-0000
Friend of Johannes Brahms (1833-1897), who stayed in his house.
R.W. Cnoop Koopmans.