Thorwald Nielsen (1891-1965) who first studied with Anton Svendsen in Copenhagen, was a member to the Danish Court Chapel since 1914 and led the Thorwald Nielsen-Kvartet as first violinist since 1924, is not only one of the founding members of 'Ny Musik' but was also quite active in the 'Kammermusikforeningen', two societies acting as organizers of concerts of the Amar Quartet in Copenhagen in 1922. Due to arm trouble, he had to give up playing the violin in 1936. Hindemith dedicated to him a 46-bar 'Prelude for violin solo' - apparently a kind of albumblatt or commemorative sheet - which, according to its characteristic style, is committed to the 4th movement from the Sonata for viola solo Op. 25/1.