Interesting question Kim. I don't have an answer for you and would be interestd in other people's knowledge. My first thought though was that it is an impossible question. How do you measure influence? 50%? 3 drachmas worth? 7 inches?

Yes the Moors had an influence on the music. That influence diminished with distance and the waning of their power. So you'll probably hear it clearest in Spanish, French and Italian music.

The other variable would be the proximity of places where music would be written and archived to places where Moorish influences were heard. There is a fair bit of music in manuscripts from the Middle Ages but a lot never survived.