Otto Singer jr. was born 14 September 1863 in Dresden (Germany). His father Otto Singer sen. (1833-1894) was a pianist and composer and pupil of Franz Liszt. In 1867 the family emigrated to America where Otto Singer sen. worked at the Cincinatti College of Music. For this reason Otto Singer jr. received his first musical education in America. He later moved back to Germany to complete his studies and was a violin pupil of Hubert Leonard and Joseph Joachim. After his studies he first worked as a conductor and composed music. Later Otto Singer jr. started to arrange piano transcriptions of operas and symphonies and became very famous for this. He was chosen by Richard Strauss or Gustav Mahler to arrange their works and also created piano transcriptions for all Beethoven and Brahms symphonies, dozens of Liszt songs, 12 Wagner operas as well as works by Bruckner, Tchaikovsky or Mozart. Otto Singer jr. died 8 January 1931 in Leipzig.
The Concertstück for violin and orchestra op.6 was first published in piano reduction in 1893, the full score most likely a bit later, both by Leuckart. I could not find any information about the year when it was composed nor provide evidence of a single performance.