Who's the most famous songwriter of all time?

Today I was jamming to some old rock in the car. Good bands like Bon Jovi, Aerosmith, Guns and Roses, Whitesnake. I had it cranked up loud and was singing along having a great time. I began to think about who my favorite band would be if I had to pick one. And I honestly don't know. I love music so much. It was kind of like trying to pick out which of my children in my favorite.

I gave up on that train of thought and began to wonder who would rank in as the most famous songwriter of all time? No clue. Narrowed my focus to Christian artists. Chris Tomlin? Then I went back in time....Fanny Crosby wrote tons of hymns. Further back - Beethoven, Handel, Mozart all composed sacred music. Further back still I found the answer. David. As in David in the Bible. His songs have endured for thousands of years. They have inspired countless other songwriters. They have been lifted and reused. (suppose the copyright has long since expired)

As a wanna be songwriter (who's still never written anything amazingly incredible) I wondered what it was that made David such a great and talented musician. After all, he was so famous as a musician that the king Saul sent for David to soothe him when he had headaches. There were plenty of musicians in the city without Saul having to bring in a young shepherd to do the job. So what made him so great? Obviously he was God-inspired, but I am very interested in studying him not as I have in the past as "a friend of God" or "the great king" or "the shepherd boy" or "adulterous murderer" but as "musician." I truly have never deeply contemplated David as a serious and amazingly gifted musician. I'll let you know what I discover. Interested in your thoughts as well.