Guiseppe Tartini - Violin Sonata in G minor, "The Devil's Trill Sonata"

Why is it called The Devil's Trill Sonata? Tartini told this story:

"One night, in the year 1713 I dreamed I had made a pact with the devil for my soul. Everything went as I wished: my new servant anticipated my every desire. Among other things, I gave him my violin to see if he could play. How great was my astonishment on hearing a sonata so wonderful and so beautiful, played with such great art and intelligence, as I had never even conceived in my boldest flights of fantasy. I felt enraptured, transported, enchanted: my breath failed me, and I awoke. I immediately grasped my violin in order to retain, in part at least, the impression of my dream. In vain! The music which I at this time composed is indeed the best that I ever wrote, and I still call it the "Devil's Trill", but the difference between it and that which so moved me is so great that I would have destroyed my instrument and have said farewell to music forever if it had been possible for me to live without the enjoyment it affords me."