Liszt Liebestrame no. 3

[Appenato]

Out of frustrated curiosity, can anyone tell me WHY Liszt wrote some notes in this piece as sharps, and then a copy of the exact same pattern following the sharped pattern, in flats??! (if that makes sense...) For example, just before the first cadenza, there's a line that has A#, D#, Fx, A#... then the following measure it's the EXACT same notes only it's notated as Bb, Eb, G, Bb, etc. WHY the change?! why not write it one consistent way instead of sharps-flats? i'm having trouble with memorizing those sections for some reason because it switches and messes my mind, even though it's the same pattern. Argh.

any reason for why composers do that? i can't understand it and it's frustrating me enormously. 

[Barbosa-piano]

 It is probably Liszt's view of the difference of harmonic expressivity between sharps and flats... Who knows... In some of Beethoven's trios, we can find an instrument playing B flat, and another playing A #, or similar cases. But that has a completely different reason, the musicians tuned their instruments a different way, in order to add expressivity to the music.

[pianohopper]

Usually it is used by composers to remind the performer that a key change is coming up, or just to give warning that they are returning to flat notation.

In this case, Liszt had no reason to switch to sharps in measure 19 (if I counted correctly) except perhaps that it would break the visual that the eighth notes have formed throughout the rest of the song.  An A natural would press up against the B natural without any breathing space.  Simply artistic license then?

This may have been Liszt's original notation, or it may have been changed to this form by editor Emil von Sauer or any number of other publishers for simple reading ease/artistry.