I just played Mozart's Fantasia in D minor and I noticed at the Allegretto section in D major, an unnecessary and confusing bass clef. So I looked on IMSLP to see if any of the editions of Mozart's Fantasia in D minor have this unnecessary bass clef. Turns out that at least 3 of the editions on IMSLP have it, and they are all editions from the 1930s and later. Editions from the 1800s, I see no unnecessary bass clef, but I do see at the Alberti bass section, a large bass clef followed immediately by a small, courtesy, treble clef. Now that isn't as confusing as the unnecessary bass clef I see in editions from the 1930s and later. The editions that I looked at and that have the unnecessary bass clef are:
- Unknown editor, no date, but looks similar in style to scores by the Mutopia Project
- Mozart Album: Zongorára, 1951
- Neue Mozart-Ausgabe, 1930-1995
All of which you can see here:
Here is an example of what I mean by an unnecessary and confusing bass clef taken from the Mozart Album edition:
The bass clef at the very end of the first volta is completely unnecessary, any decent pianist is going to know that the repeat starts in the bass clef and changes to the treble clef later on. But that isn't what makes this bass clef confusing. No, what makes it confusing is that it makes it look as though the Alberti bass starts in the bass clef on an F# minor harmony when in fact it starts in the treble clef on a D major harmony. If the editor just didn't put in this unnecessary bass clef, it would be very clear that the Alberti bass starts in the treble clef on a D major harmony.
So, why am I seeing this unnecessary and confusing bass clef almost universally in editions of Mozart's Fantasia in D minor from the 1930s and later? I have seen a lot of courtesy clefs and clef changes, but until I looked at this piece, I have never seen a case where a clef makes things more confusing.