Thank you for the nice words, mikee!
In my book, no. 13 in is C Major, and in the contents at the beginning of the book, it says that no. 15 is in F Major, when in fact it is in D-minor. What is very weird to me, is that I changed the last chord in my recording of no. 15. My brain somehow thought there was a sharp sign in front of the F and so I played a nice, pretty D-major chord there, which of course changed the entire feel of the piece. It's supposed to be a D-minor chord which then makes the piece end in sadness. I really can't understand why I did that - strange things have been happening lately. But the good news is that because you brought my attention to no. 15, I found my mistake and have just now re-recorded the ending and corrected that last chord. So I'm thanking you big time!!