Who is Ralph Leighton from Surely You're Joking, Mr. Feynman! and what is their importance?

Although "Surely You're Joking, Mr. Feynman" is clearly a first person account from Dr. Feynman's point of view, Ralph Leighton is credited as co-author. The book could be seen as a series of incidents in Feynman's life as related to (and probably edited and arranged by, to some extent) Ralph Leighton.

Ralph Leighton appears as a character only once, in the chapter entitled "Found Out in Paris". We learn that Mr. Leighton is a drummer, and that this is how the two meet. The chapter tells us the two of them collaborate on several drumming projects. Although Mr. Leighton is a friend Dr. Feynman meets through one of his non-scientific endeavors, the fact he has collaborated in the writing of such a multi-faceted book suggests that he, like Feynman, may have a very wide range of interests.