This collection belonged to the anatomist and amateur violinist Guido Richard Wagener (1822-1896) and was purchased in 1901 by Alfred Wotquenne, librarian of the Conservatoire royal de Bruxelles. Wagener collected a large range of different music, but his main interest was German repertoire. The collection contains over 9,000 works, collected up until Wagener’s death in 1896. In addition to the music collection, he also collected tools for research and books about anatomy, musical instruments and iconographic documents. His collection of instruments was destroyed during the Second World War, while his collection of musical iconography was split up and sold in 1982. The collection of musical works is the largest and most significant collection of "foreign" music in Belgium. Together with the Westphal collection, the Wagener collection constitutes the heart of the historic heritage conserved in the libraries of the conservatoires of Brussels.
The Wagener collection contains works by Carl Philipp Emanuel Bach including a number of major works of which four – perhaps five – are autograph manuscripts.