How is the sheet music made?

Arinaud, a visitor of this blog, asked me in the comment section: “Which app are you using for the scores ?”. 

Well, I decided to tell you all about it.

First of all, I record the phone screen while playing a song to  a mp4 video file.

Then, I use that mp4 video file as input for a simple program that I wrote in Python using the openCV library. This program runs for a couple of minutes and it outputs a jpg file that is a picture of a long strip of the Duolingo sheet music, as you can see:

I could crop and paste sections of this image to make a sheet music like this:

S003U001L010 Bicycle Built For Two-DUO

But, it's faster to transcribe it with museScore 3, it takes me about 10 minutes to do that. So I open the strip file in the paint app and scroll the strip horizontally while writing the notes on the app museScore 3.  When the score is ready I export it to a *.png file like this:

S003U001L010 Bicycle Built For Two-1

That 's all folks.