The Concerto in A Major for Clarinet and Orchestra, K. 622 by Wolfgang Amadeus Mozart (1756-1791) is universally recognized as a timeless musical masterpiece. This was the last concerto written by Mozart, and it was completed just two months before his premature death at the age of 35.
Mozart composed the concerto for his friend and fellow Freemason, clarinetist Anton Stadler (1753-1812). It is reported that Stadler had a special A clarinet that extended below the traditional range. Just as is the standard today, the typical A clarinet in 1791 went down to a written low E below middle C (concert C#). Stadler’s instrument extended down an additional minor third to a written low C (concert A). It is speculated that Mozart utilized the special low range on Stadler's instrument in the concerto.
For over two centuries, there has been much written and debated about the concerto. The mystery of the concerto stems from the fact that Mozart's original manuscripts went missing in 1791 and have never been found. The earliest edition dates from 1801 by the German publisher, Johann André. The André edition only extends to a written low E. It is speculated that if Stadler's original part utilized the extended low range, that the first publisher may have revised the solo part to reflect the traditional range, in order for their edition to be commercially viable, but the truth may never come to light. Without a manuscript to study, the questions regarding the authenticity of the range, articulations, dynamics, and phrasing will always exist. So, it is incumbent upon each player to create their own interpretation and musical nuances.
What edition should you buy and perform? There are many from which to choose. Young players should consult their teacher for specific recommendations. More experienced players can collect editions (like me!) and make personal decisions as to which version(s) they prefer. Each player will ultimately customize their own edition. In any case, keep in mind that this work was composed for the A clarinet and every effort should be made to play this work on the A clarinet. Many young players begin learning the concerto on the B-flat clarinet simply because they do not have an A clarinet. The written notes for the clarinet remain the same, but the piano accompaniment is transposed accordingly. A full realization of the concerto can only be achieved with an A clarinet, both for the intended key and unique timbre of the A clarinet.
Since the latter part of the twentieth century, several instrument makers have manufactured A clarinets with an extended low register, mirroring Stadler’s instrument. These instruments are commonly known as “basset clarinets” in A. Additionally, a number of new “reconstructed” musical editions have been prepared and published that incorporate numerous passages where the range extends below the established editions, which were modeled after the original André edition. No matter which instrument or edition you utilize, playing the Mozart Clarinet Concerto is a great musical experience.
There are many superb recordings of the concerto. My personal favorite on a traditional A clarinet was recorded in 1961 by the brilliant clarinetist Robert Marcellus with the Cleveland Orchestra conducted by George Szell.
Several excellent recordings have also been made featuring the basset clarinet in A, including this one performed by the remarkable virtuoso, Julian Bliss.