Hans Gál wrote 'Impromptu' in Edinburgh in August 1940 for his then 15-year-old son Peter. His son had already taken several violin lessons and now wanted to try to play the viola in order to join a youth orchestra. As a consequence, 'Impromptu' is easy to play, and its Romantic harmonies in the equally easy piano accompaniment make the piece a well sounding duo that can even be performed by beginners. The Austrian composer and musicologist Hans Gál (1890-1987) composed operas, orchestral works, concertos, vocal music and, especially in the last decades of his life, numerous chamber music works. In addition, he published books (Brahms, Schubert, Verdi) and essays. When Gál was forced to leave Germany in 1933, he first moved to Vienna and finally settled in Edinburgh where he composed and taught at the university until his death.