A. I don’t have to figure that at all.
Then who do you think did? (typical Jewish response – a question with a question)
B. Even if so, have you ever heard anyone lain Tehillim with the trup?
C. Even if you did, how do you know the tune used for the trup then is the same as is used today?
My point was that he probably did write music, not that I ever heard it, although I can only imagine that it was spectacular.
I think wanderingchana makes a great point (not sure if you caught it)- why would it be called Mizmor if it was not a musical composition? Many kapitlach begin “Mizmor” or “Lam’natzeiach” (to the conductor). Then again, maybe the m’natzeiach wrote the trup?