T50 D major [I make no claims to originality. The songs in these pieces are adapted. The original song appears in the bass clef. The only claim I make is I like to write and to share music.] Most often the song that is in the upper clef that is heard to some kind of inverse of the original song. Sequences that go up I turn to going down. I do all kinds of variations based on what I learned from Mozart scores. There is no claim of originality except that these songs have never been heard before.
here in this link I change the clefs so the original song can be heard. In my opinion my change of the originals is slightly better. But that is just just me. [You will notice I all kinds of variations with view to improve the piece, but claim nothing in terms of originality.]

For a long time I simply used my own Songs that I thought up while walking outside. But anyway they were influenced by the music I was playing on the violin. People thought the songs were not original even though they were! The reason I I was anyway basing my song on themes I had seen while playing Mozart. So at some point after the E series I simply started looking at Renaissance Musik and adapting the themes in ways I thought were improvements. That is using the idea of inverse directions and also ideas I had seen in Mozart. For example Mozart sometimes prefers to go to a 6th when you would expect a 5th. That is one example I specifically use in this piece T50. Another thing Mozart does is to go to a 1-3-5 chord when you would expect a chromatic progression. I also use that idea here. There are tons of ideas like that in every single Mozart piece which anyone could dig up an adapt if they wanted to. [Bach I found a lot harder to figure out.]