José,
you are right; of course I didn't always use midifiles as a starting point. For example, to record Wave I did use an arrangement found in a magazine named "European Musician" (now discontinued); there was a guy who proposed to play this song with different voicings; I really liked them and so have spent hours trying to learn them. On the other hand all the rest (guitar solo included) is my own stuff.
The same goes for Malafemmena: I don't know if -unconsciously- I took inspiration from someone, but things went very simply: I began to record the song with the rhytm track, then started playing a jazz guitar sound and I found myself playing those jazzy chords without even knowing. When I did listen to the registration I was amazed to hear how good it sounded.
On the other hand, even if you go inside a museum, you will find painters trying to copy all those masterpieces hung on the walls. Once you've learned the technique, you are ready to start your own (hopefully creative) artistic work.