This sonata is presented here in its original key of C major.
The only note changes in the Concert Version of the first movement are the following: some additions of the open C string in chords (bars 1, 5, 100 and final), the revoicing of some chords (final bars of each section), the conversion of some trills into either turns or mordents (bars 42, 78-83, 122, 124) and – the most radical – the placement of a chord on the first note of the re-exposition (bar 95), just like at the beginning of the piece. My apologies to Mozart, but I think it is “better” like that. Perhaps he deliberately left the chord out in order to disguise the return to the re-exposition, making it a comic surprise …… if so, then I apologise for my lack of humour! But it could have been a simple mistake (oversight) …..
In the “Clean Concert Version” all of Mozart’s trills have been removed in order to allow us to decide whether (and when) we might prefer to play turns or mordents instead of the trills. Many of the trills are on notes that are just too short for a normal cellist to be able to trill safely and comfortably.
The “Easier Version”, apart from the usual octave transpositions down of all Intermediate and Thumb Position passages, has had a lot of simplification of the rapid ornaments: almost all trills have been turned into mordents or turns. If some of the tricky passages with grace notes are too complex, we can easily just remove those grace notes. It is easier to remove notes from a part than it is to write them in. In bars 62 and 147 the direction of the string crossing oscillation has been inverted to make this bowing easier.
Of the total 71 bars in this movement, approximately 50 have been transposed up an octave, including the first 24 bars. These passages, that were originally in the bass-register of the violin, now lie in the tenor (rather than the bass) register of the cello and are played at exactly the same pitch as in the original violin version..
Here, many of the numerous grace notes and ornaments have been notated rhythmically, sometimes to eliminate ambiguity (grace notes), other times to allow the placement of fingerings (turns) and other times to clarify the conversion of trills into turns with apoggiatura. In this movement the very same notation (of a grace note before the beat) can give us three quite different effects depending on whether we play it on the beat or before the beat, and for how long we play it:
The note changes made in this movement concern: the quaver upbeats to bars 161 and 163 (removal of double-stop and transposition down an octave) in order to give us time to get across the strings to the next double-stop, the simplification of trills into turns (bars 92-97) or single grace notes (bars 5-6, 58-59, 141-142), and the addition of a grace note in bars 86 and 88.
The “Easier Version” stays always in the Neck Region thanks to some octave transpositions down.