Avid listeners of classical music will have probably noticed that tastes change over the years. Pachelbel's Canon in D now trips delightfully rather than wallowing majestically, and the slow movement of Mozart's Clarinet Concerto has also had a firework put up its tail. Something else that only the closest listeners will have noticed is that the Clarinet Concerto also sounds different to how it used to, almost as though it doesn't have the same notes at all...

Changing Instruments

Mozart was a great composer, and like many composers had a close relationship with virtuosi of his day. His affinity with the clarinet stems partly from his closeness to Anton Stadler (1753–1812). Stadler was a gifted clarinettist who had a reputation for producing a glorious tone, and who specialised in playing second clarinet, rather than first, in orchestras.

You may think that the second clarinet part falls to the less talented player, but this isn't always the case; the clarinet is a strange beast and the second clarinettist has to have a particular mastery of the middle and lower ranges. Stadler not only revelled in the bottom end of the instrument but worked with a maker, Theodore Lotz, to extend it even further. Rather than having the lowest note as E¹, he pinched the idea from the basset horn² to go all the way down to bottom C³. It may only have been an extra four semitones, but it opened up a whole new sound world for Mozart who included these extra notes in his Clarinet Concerto, the Clarinet Quintet, his opera La clemenza di Tito, and possibly in other works too. To see what it may have looked like, watch this video of extracts from the Concerto, played by Oscar Arguelles.

Why Did Things Change?

Stadler's extended clarinet sadly didn't catch on. If other players wanted to play the Concerto, they couldn't play certain passages as they were written. Mozart died just seven weeks after the premiere of the Concerto in 1791, and Mozart's publishers 'fixed' these passages when it was published posthumously in 1802. The original manuscript was lost. The legend goes that Stadler, in his later life, pawned it. If it's also true that he stole the manuscript and money from Mozart in the first place, it's possible that Mozart didn't pick a particularly loyal friend.

This amended version was the standard one played by everyone until musicologists, researching the origins of the concerto, realised that it wasn't the original. The earliest of these researchers was in 1948, and by 1977 the first full copy of the Concerto was printed with the clarinet and basset clarinet versions side by side. Gradually more and more players have decided to buy (or have made) clarinets with the extra notes specifically to play the Concerto, with it starting to become more mainstream in the 1990s. We will never know exactly what Stadler's version sounded like, but this version is now becoming standard in concert halls and on the radio.

Is It Better?

Gosh yes. Passages that leapt all over the place now run beautifully up and down the range of the instrument, making much more musical sense. From a player's perspective there are also passages that have been restored to sonorous parts of the instrument, rather than clattering around in the poorest and drabbest reaches. Stadler's version - that is, with the lower notes - still isn't played by everyone, as not all players can fork out for a brand new instrument, but when you compare them side by side there is no comparison.

For example, listen to about twenty seconds of this version, played by Stanislav Chernyshev⁴. It is well played, but can you hear that the passage occasionally jumps up an octave in the middle of a phrase? Now listen to the same passage again here, this time played by Anthony Taylor⁵. This time the passage is a lot smoother, and drops down much lower.

As musicologists research and learn, musical interpretations of many pieces of music will change. For some people though, restoring the Mozart Clarinet Concerto to something approaching its original glory is one of the best things they have ever done.