Thank Richard and Thomas, it works!
I report here what I did in case others have the same problem (and like me are beginner):
- open the file changePitch.ly in frescobaldi
- then menu "Tools/Update with convert-ly..."
- in the dialog box, in the "From version", enter 2.18.0 and in the "To version" enter 2.19.35"
etc.
Best regards, g.