In 1992, a program for a concert given by Anton Stadler in Riga in March of 1794 was discovered, where he played the Mozart Clarinet Concerto. Amazingly, this program includes an engraving of the special 'Inventions Klarinette', or basset clarinet, that Stadler had with him to play Mozart’s music. Up until this time, no one knew what the basset clarinet looked like, and it came as a shock to see a long instrument with a bulbous bell on the end.

This new release on the Glossa label is the first time the work will appear played on an instrument like what Stadler possessed.