[itsme]

We should be aware that there are different cases to consider:
Transposing the displayed song vs. transposing in the text editor. Both is possible with ChordPro files and with .txt files. ChordPro files can additionally contain chord grid and ABC sections.
When we report issues it's crucial to mention which situation we are talking about, sample files might be of help.

My findings so far:

Transposing ChordPro files in song display works fine, including ABC and chord grid sections. There are only very minor questions: if handling accidentals for the whole song with the sharp / flat buttons is sufficient and if replacing E# / Fb / B# / Cb with their enharmonics is OK. For my personal use cases there's no need to change something. I'm curious if erhe really is able to come up with a better algorithm.

Transposing ChordPro files in text editor is confusingly buggy, see https://www.zubersoft.com/mobilesheets/f...13197.html  as mentioned before. This should be fixed to work as similar as possible to transposing in song display.

I have not yet investigated in detail the behaviour when .txt files are used. I always use ChordPro.