If you can use your ear, man, use it. Let some other
mother put it down
 on paper. 
When I was learning to compose in school, I spoke of the experience to
a friend.  He was the sort of musician that would take a four-track,
lay down some guitar, then sing over it etc.  and call it a composition.
I was explaining to him that part the process that I would go through
was to learn how to play a piece once it was *written*.
He looked surprised, and with a bit of pride he said that he had
never written anything that he could not play.  I said that I had
only written things that he could not play.
Tobiah