This post is to highlight differences in the sorting methods used by other music control apps. I cannot say what is correct but rather what many people will expect.
BubbleUPNP / Linn Kinsky / Lumin sort alphabetically case insensitive
Glider sorts case sensitive
In addition, Glider sorts non alphabetic characters last as opposed to first as per the other named apps. Yes, the right hand side index enables them to be found quickly but may catch people out initially.
Personally, I prefer the Glider approach.
Unlike the Album, Artist, Songs categories, the Composers and Genre categories do not have a right hand side index.